Move ERC test utilities to common file

Move ERC test utilities to common file

* lisp/erc/erc-common.el (erc--define-catalog): Update name of
reference to convenience command now located in `erc-tests-common'.
* test/lisp/erc/erc-button-tests.el: Require common test-util library
`erc-tests-common', located under test/lisp/erc/resources.
; (erc-button-alist--url,
; erc-button-tests--erc-button-alist--function-as-form,
; erc-button-tests--erc-button-alist--nil-form,
; erc-button--display-error-notice-with-keys): Use common helper
; `erc-tests-common-init-server-proc' from test-utils library.
* test/lisp/erc/erc-fill-tests.el: Require `erc-tests-common'.
(erc-fill-tests--wrap-populate): Use helper
`erc-tests-common-init-server-proc'.
(erc-fill-tests--save-p): Remove.  See replacement
`erc-tests-common-snapshot-save-p' in erc-tests-common.
(erc-fill-tests--graphic-dir): Add trailing slash.
(erc-fill-tests--compare): Move body to generalized utility
`erc-tests-common-snapshot-compare' in erc-tests-common.
* test/lisp/erc/erc-goodies-tests.el: Require `erc-tests-common'.
(erc--get-inserted-msg-beg/readonly,
erc--get-inserted-msg-end/readonly,
erc--get-inserted-msg-bounds/readonly): Move here from erc-tests.el.
* test/lisp/erc/erc-networks-tests.el: Load `erc-tests-common'.
(erc-networks-tests--create-live-proc): Defer to
`erc-tests-common-init-server-proc' and drop optional buffer param.
(erc-networks-tests--clean-bufs): Defer to
`erc-tests-common-kill-buffers'.
(erc-networks--rename-server-buffer--existing--live): Call
`erc-networks-tests--create-live-proc' in server buffer.
* test/lisp/erc/erc-scenarios-internal.el: Load `erc-tests-common'.
(erc-scenarios-internal--run-graphical-all): Use
`erc-tests-common-create-subprocess' to create process.
* test/lisp/erc/erc-scenarios-sasl.el
(erc-scenarios-sasl--plain-fail): Silence error message.
* test/lisp/erc/erc-stamp-tests.el: Require `erc-tests-common'.
(erc-stamp-tests--insert-right, erc-timestamp-intangible--left): Use
`erc-tests-common-init-server-proc'.
(erc-tests--assert-get-inserted-msg/stamp,
erc-stamp-tests--assert-get-inserted-msg/stamp): Move from
erc-tests.el, renaming to latter.
(erc--get-inserted-msg-beg/stamp,
erc--get-inserted-msg-beg/readonly/stamp,
erc--get-inserted-msg-end/stamp,
erc--get-inserted-msg-end/readonly/stamp,
erc--get-inserted-msg-bounds/stamp,
erc--get-inserted-msg-bounds/readonly/stamp): Move here from
erc-tests.el.
* test/lisp/erc/erc-tests.el: Require `erc-tests-common'.
(erc-with-server-buffer): Use renamed test-helper utility
`erc-tests-common-init-server-proc'.
(erc-tests--send-prep, erc-tests--set-fake-server-process): Move to
`erc-tests-common' library and rename to
`erc-tests-common-prep-for-insertion' and
`erc-tests-common-init-server-proc', respectively.
; (erc-hide-prompt, erc--refresh-prompt,
; erc-setup-buffer--custom-action, erc--parsed-prefix,
; erc--update-channel-modes, erc--channel-modes,
; erc--channel-modes/graphic-p, erc-ring-previous-command): Use
; `erc-tests-common-prep-for-insertion' instead of
; `erc-tests--send-prep', and use `erc-tests-common-init-server-proc'
; instead of `erc-tests--set-fake-server-process'.
(erc-tests--with-process-input-spy): Move to `erc-tests-common' and
rename `erc-tests-common-with-process-input-spy'.
; (erc--check-prompt-input-functions, erc-send-current-line,
; erc--check-prompt-input-for-multiline-blanks,
; erc-send-whitespace-lines): Use renamed
; `erc-tests-common-with-process-input-spy' and
; `erc-tests-common-init-server-proc'.
; (erc-process-input-line): Use renamed
; `erc-tests-common-init-server-proc'.
(erc-tests--get-inserted-msg-setup,
erc-tests--assert-get-inserted-msg,
erc-tests--assert-get-inserted-msg/basic,
erc-tests--assert-get-inserted-msg-readonly-with): Move to
`erc-tests-common' and rename with "common" prefix, using single
instead of double hyphen.
(erc-tests--assert-get-inserted-msg/stamp): Move to `erc-stamp-tests'
and rename with "stamp" prefix.
(erc--get-inserted-msg-beg/stamp,
erc--get-inserted-msg-beg/readonly/stamp,
erc--get-inserted-msg-end/stamp,
erc--get-inserted-msg-end/readonly/stamp,
erc--get-inserted-msg-bounds/stamp,
erc--get-inserted-msg-bounds/readonly/stamp): Move to
`erc-stamp-tests'.
(erc--get-inserted-msg-beg/readonly,
erc--get-inserted-msg-end/readonly,
erc--get-inserted-msg-bounds/readonly): Move to `erc-goodies-tests'.
; (erc--get-inserted-msg-beg/basic,
; erc--get-inserted-msg-end/basic,
; erc--get-inserted-msg-bounds/basic): Use common helpers.
; (erc--route-insertion): Use renamed helper functions
; `erc-tests-common-with-process-input-spy' and
; `erc-tests-common-init-server-proc'.
(erc-tests--make-server-buf): Move to `erc-common-tests' and rename
with "common" prefix.
(erc-tests--make-client-buf): Remove unused function without supplying
replacement.
; (erc-handle-irc-url): Use renamed `erc-tests-common-make-server-buf'
; utility function.
; (erc-tests--assert-printed-in-subprocess): Use helper from common lib
; `erc-tests-common-create-subprocess code' to do the heavy lifting.
(erc-tests--string-to-propertized-parts,
erc-tests-pp-propertized-parts): Move to `erc-tests-common' and rename
with "common" prefix.
* test/lisp/erc/resources/erc-tests-common.el: New file containing
helper utilities and fixtures used by multiple files in test/lisp/erc.