RPRUN-150 Clean-up and improve code (#48)

* Drop Content directory with materials and old uber

* Drop outdated Documentation and outdated GLTF test

* Drop old UBER and UVs modules

* Remove outline and UVEditor directories

* Drop unused plugin

* Improve *.uplugin and *.uproject files

* Drop old plugin content directory

:Release Notes:

:Detailed Notes:
Drop old content directory
Replace LICENSE.txt with apache2 license

:Testing Performed:
No tests

:QA Notes:

:Issues Addressed:

Signed-off-by: Maksym Sditanov <[email protected]>

* LICENSE.txt: use apache license

:Release Notes:

:Detailed Notes:

:Testing Performed:
No tests

:QA Notes:

:Issues Addressed:

Signed-off-by: Maksym Sditanov <[email protected]>

* Drop outdated docs

:Release Notes:

:Detailed Notes:

:Testing Performed:
No tests

:QA Notes:

:Issues Addressed:

Signed-off-by: Maksym Sditanov <[email protected]>

Author: feniksa