Fix T65914: Workbench Transparency Film

When performing F12 render on a transparent film all solid objects where
a bit transparent. Single Pass AA and no AA passes were not visible at
all.

Issue was that the first frame was not handled correctly making these
artifacts. This commit changes the order of `GPU_state_init` and
`DRW_state_reset` so the state is correct during the first pass.

TexturePaint: Projection Edit

Disable all overlays except the texture paint overlay. Add alpha to the
resulting image buffer.

Reviewed By: brecht

Differential Revision: https://developer.blender.org/D4974

Compositor: File output node sockets

When using RNA to alter the type of socket only the type was changed.
the typeinfo was not updated. Internally the File Output Node used RNA
to update the sockettype. making the socket invalid. When users save the
file and reopened the typeinfo was used. Also the color of the node was
determined via the typeinfo.

Another thing that happened was that the socket conversion was ignored
when empty node groups were present. The empty node groups were
optimized away before the needed data conversion was determined.

Reviewed By: brecht

Differential Revision: https://developer.blender.org/D4938

Fix T65763: Reset GPU when exporting annotations

When exporting annotations using `bpy.ops.render.opengl` the annotations
where only correct in the first frame. In the second frame the
annotations was shifted by half the resolution.

This change will reset the GPU matrices when the annotations are
rendered.

Typos in description

Documentation: Update description with documentation

DrawManager: OpenGL State Image Rendering

The OpenGL state was not set to blender defaults when using
`DRW_render_to_image` path. This is only used when doing F12-rendering.
Cause of changes with the `RESTART_INDEX` hair rendering was rendering
the restart_index as an actual vertex index.

Reviewed By: fclem

Differential Revision: https://developer.blender.org/D5039

Sequencer: Typo

Sequencer: Viewport Rendering Annotation

When rendering the Sequencer using viewport rendering the annotations
were not scaled to respect the scene render size. This was because the
matrices were calculated based on the output size and not the actual
rendersize.

Reviewed By: brecht

Differential Revision: https://developer.blender.org/D5032

Python: GPU Offscreen Rendering

When using python offscreen rendering the background was not drawn in
EEVEE. Users would expect that when calling the `draw_view3d` method
that it shows the same as in the 3d viewport.

Seems to be a difference between the meaning of draw_background in b279
and b280. In B279 the world background would be drawn. In B280 the
transparency is changed.

Reviewed By: campbellbarton, fclem

Maniphest Tasks: T61768

Differential Revision: https://developer.blender.org/D5022