UI: Add configurable prefix/suffix for Screenshots
Description
Provides prefix & suffix configuration fields for screenshots in Settings -> Advanced, alongside Replay Buffer.


Motivation and Context
Feature parity and better ability to organise files.
Additionally, as the OBS output defaults to the Videos folder on the system, it doesn't make sense to force the user to put screenshots in there too.
How Has This Been Tested?
- Set a screenshot hotkey
- Change the prefix or suffix, Save & close the Settings dialog
- Press the screenshot hotkey
Types of changes
- New feature (non-breaking change which adds 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.
Why just prefix/suffix? Why not have an entirely separate output location config for each of these?
That's certainly something we could do, yeah. Replay Buffer already has a section in Settings -> Output, adding another tab/section for Screenshots would be doable. I'll have to look into how heavily the path generation functions depend on the existing shared path.
Edit: Not something that could be ready by 26 though.
I have never been particularly happy about the buffer being a prefix/suffix rather than a full separate path. If we can update so all 3 are separate paths, I think that is ideal.
I am very reluctant to accept this in the current form. Would it be possible to update this to be separate/unique paths and filenames, or should this be closed in favor of a new PR?
That would be the ideal implementation, yes. I'll close this PR for now to give someone else the opportunity to potentially implement it.