Add a texture inspector and show it when hovering over an inventory textory (or folder containing - among others - exactly one texture) and when hovering over notecard embedded textures

following promotion of DRTVWR-565

Cleaner reinit and termination.

Fix a thread safety issue in the GL image worker.

LLViewerTexture::mNeedsCreateTexture needs to be an attomic bool since
it is written both in the main thread and in the GL image worker thread.

We can now enable threaded bump maps creation as a result of this fix.

I have read the CLA Document and I hereby sign the CLA

Various repo fixes

Add automatic PR labels

Add CLA bot

original fix by Beq Janus

Due to udp texture fetching no longer being present

following promotion of DRTVWR-575

Fix SL-18511 TOS and MFA login failure handlers must cooperate to answer both reasons at the same time

following promotion of DRTVWR-574

following promotion of DRTVWR-548

Since the performance overhaul project, there should be essentially no difference between rigged meshes and non-rigged as far as vertex buffer management is concerned.