Add display option for interactive ERC invocations

Add display option for interactive ERC invocations

* lisp/erc/erc.el (erc-buffer-display, erc-receive-query-display):
Add aliases for `erc-join-buffer' and `erc-auto-query'.
(erc-interactive-display): Add new option to control display of server
buffers during interactive entry-point invocations.
(erc-select-read-args): Pass `erc-interactive-display' to entry
points.
* test/lisp/erc/erc-tests.el (erc-select-read-args): Expect
buffer-display values from `erc-interactive-display'.
(erc-tls, erc--interactive): Also check `erc-join-buffer' in
environment when `erc-open' called.  (Bug#60428.)