Improve `GetIndexedField` in protobuf

[izveigor]

Is your feature request related to a problem or challenge?

Follow on to #6936.
The current implementation GetIndexedField in protocol buffer does not support optional argument extra_key (except of this, GetIndexedField supports only two required arguments).

So, what we should do:

• We can call GetIndexedField in protocol buffer without extra_key (like index[i])
• We can call GetIndexedField in protocol buffer with extra_key (like index[i:j])

Describe the solution you'd like

No response

Describe alternatives you've considered

No response

Additional context

No response

[parkma99]

I would like to take it.

[izveigor]

Thank you, @parkma99!
You can implement it after merging PR: #6936.

[izveigor]

I'm sorry, @parkma99! I already solved this problem during refactoring (#7215).

[parkma99]

Every thing is OK, I am at home this week.