Transform Feedback Command Tree Grouping

[pmuetschard]

Traces of applications where in the beginning of each frame transform feedback draw calls are used (e.g. for animation) will have multiple "draw call" groupings at the beginning of the frame with the "invalid FB data pattern" as the thumbnail.

• Rename the grouping to indicate that the draw call is for transform feedback
• Gapis needs to tell the UI not to show a thumbnail for these groups