In `get_terms()`, do not override 'hierarchical' and 'pad_counts' when 'parent' is present.

The previous behavior resulted in descendant terms being improperly excluded
from the results when passing a 'parent', even when 'hierarchical' had been
set to true.

The patch also adds unit tests that demonstrate the various interactions
between the 'child_of', 'parent', and 'hierarchical' parameters of `get_terms()`.

Props landakram.
Fixes #29815.
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git-svn-id: http://core.svn.wordpress.org/trunk@30107 1a063a9b-81f0-0310-95a4-ce76da25c4cd
Clean up `get_term_by()` caching.

* Fix cache key/group modification that was missed in [30073].
* Update unit tests to reflect new key/group format.

Props tollmanz.
Fixes #21760.
Built from https://develop.svn.wordpress.org/trunk@30108


git-svn-id: http://core.svn.wordpress.org/trunk@30108 1a063a9b-81f0-0310-95a4-ce76da25c4cd
Update the changelog for `get_approved_comments()` to reflect that the function was refactored to leverage `WP_Comment_Query` in [30098].

Also updates the `$args` parameter description with a reference to see `WP_Comment_Query` for argument information.

See #12668.

Built from https://develop.svn.wordpress.org/trunk@30109


git-svn-id: http://core.svn.wordpress.org/trunk@30109 1a063a9b-81f0-0310-95a4-ce76da25c4cd