## Description 

This PR adds handling of shadowed variables to the trace viewer:
- shadowed variables appear in separate scopes
- shadowed scope appears when a variable with the same name as an
already existing one is declared
- shadowed scope disappears when all variables it includes stop being
live

Additionally, this PR (temporarily) suppresses on-hover information that
VSCode shows during debug session. The reason for it is that the default
VSCode behavior in this department breaks in presence of shadowed
variables

## Test plan 

Tested manually