Fixes the `load_script_textdomain` function not resolving the md5 hash based on the relative path for WordPress installations in a subdirectory. Also adds a filter to allow sites using CDNs or other alternative asset locations to filter the relative path resolution.
Props akirk, fierevere, swissspidy, mypacecreator, babaevan, tmatsuur, ocean90, herregroen.
Merges [44209] to trunk.
Fixes#45528.
git-svn-id: https://develop.svn.wordpress.org/trunk@44310 602fd350-edb4-49c9-b593-d223f7449a82