Support more metadata properties in completion-extra-properties (bug#68214)

Support more metadata properties in completion-extra-properties (bug#68214)

* doc/lispref/minibuf.texi (Completion Variables): Add
to the table of completion-extra-properties new items:
`group-function', `display-sort-function', `cycle-sort-function'.

* lisp/icomplete.el (icomplete--augment): Remove unnecessary
plist-get from completion-extra-properties since now
completion-metadata-get does this.

* lisp/minibuffer.el (completion-metadata-get): Use plist-get to
get prop from completion-extra-properties and cache the keyword.
Thanks to Daniel Mendler <mail@daniel-mendler.de>.
(completion-extra-properties): Mention new properties in docstring.
(minibuffer-completion-help): Remove unnecessary
plist-get from completion-extra-properties since now
completion-metadata-get does this.

* lisp/net/eww.el (eww-switch-to-buffer):
* test/lisp/minibuffer-tests.el (completions-affixation-navigation-test):
Unquote lambda in completion-extra-properties.