Initial FFMPEG Wrappers Unification Process

See the phabricator post for more details.

This is a work in progress, I'll put more details on what this entails here in the future.

• Use KisFFMpegWrapper inside of KisVideoSaver (now renamed KisAnimationVidioSaver). Replaces KisFFMpegRunner.
  • Polish pass.
• Use KisFFMpegWrapper inside of RecorderDocker.
  • Polish pass.
• Move FFMpeg path setting to configuration menu w/ shared concept of executable path.
• Probably more.......

Test Plan

TODO

Formalities Checklist

• I confirmed this builds.
• I confirmed Krita ran and the relevant functions work.
• I tested the relevant unit tests and can confirm they are not broken. (If not possible, don't hesitate to ask for help!)
• I made sure my commits build individually and have good descriptions as per KDE guidelines.
• I made sure my code conforms to the standards set in the HACKING file.
• I can confirm the code is licensed and attributed appropriately, and that unattributed code is mine, as per KDE Licensing Policy.