Node Wrangler: Fix T65202: keymap conflicts

Since CTRL+LMB is now taken by 'cut links' in blenders default keymap,
this was conflicting with nodewranglers 'lazy connect' and unfortunately
we have to step aside here.

This commit shifts shortcuts:

lazy connect (CTRL+LMB --> ALT+RMB)
lazy connect with menu (CTRL+SHIFT+LMB --> ALT+SHIFT+RMB)
lazy mix (ALT+RMB --> CTRL+SHIFT+RMB)

This keeps the two 'lazy Connect' on a common "base" key and just moves
'lazy mix'