cmake: Handle copy and install of locale files

[RytoEX]

Description

Copy and install the locale files for enc-amf.

Motivation and Context

Want plugins to not break.

Normally, the new OBS CMake helpers would handle this, but those expect locale files to be in data instead of resources. We considered moving the locale files from resources to data, but other things, such as https://github.com/obsproject/obs-crowdin-sync/, have special handling for enc-amf, and I didn't want to worry about what else would break.

How Has This Been Tested?

Built locally.

Types of changes

• Bug fix (non-breaking change which fixes an issue)
• Tweak (non-breaking change to improve existing functionality)

Checklist:

• [x] My code has been run through clang-format.
• [x] I have read the contributing document.
• [x] My code is not on the master branch.
• [x] The code has been tested.
• [x] All commit messages are properly formatted and commits squashed where appropriate.
• [x] I have included updates to all appropriate documentation.