This is achieved by using `lock_repo`
context manager that can be used in a recursive depth
that only resets stages when it has left any lock_repo
blocks.
Also added some ui related tests for the status which I found
missing
* don't allow loading stages without `cmd`
This was loosened when introducing parametrization.
But, `foreach`..`do` should be considered first
before stage's regular structure. And, cmd is made
required (as it should have been)
Related: #5371, #5370, #5312
* fix schema
Saugat Pachhai (सौगात)
Ruslan Kuprieiev
nik123