Vertex Weights small improvements

In the Vertex Weights menu ("Edit mode" -> Select any vertex with weights -> Sidebar ("N" pannel), "Item" tab) it would be nice to have two additional options:

1. Information about the sum of all weights.
2. Ability to make the normalization of weights with some number of locked weights - if any of the vertex groups is locked, it can not be changed, and normalization occurs only for non-locked vertex groups (but taking into account locked weights).