Accept "latest" and "finalized" as block number values for debug_traceBlockByNumber method

[rubo]

Resolves #4133

Changes:

• debug_traceBlockByNumber now accepts latest and finalized as a block number value
• debug_traceBlock, debug_traceBlockByNumber, and debug_traceBlockByHash methods has been unified and refactored

Types of changes

What types of changes does your code introduce?
Put an x in the boxes that apply

• Bugfix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to not work as expected)
• Documentation Update
• Code style update (formatting, renaming)
• Refactoring (no functional changes, no api changes)
• Build related changes
• Other (please describe):

Testing

Requires testing

• Yes
• No

In case you checked yes, did you write tests??

• Yes
• No

Comments about testing , should you have some (optional)
Test cases has been added for debug_traceBlock, debug_traceBlockByNumber, and debug_traceBlockByHash methods.

Further comments (optional)

Further refactoring, unification, and new test cases on the Debug module will be done along with the other sub-tasks of #4210.

[LukaszRozmej]

Comment: I think you are using different IDE configuration changing things to var and different spaces layout, maybe lets unify?

We consider var easier to read (you don't have to guess what is there) especially when doing reviews through github, where there is no IDE to hint you.