Added better node position logging

[TeemoKill]

What problem does this PR solve?

Maybe #910 -> How do I get the position of an AST node.
The previous solution logged the starting offset of the original text,
this pull request added more detailed position information to ast.Node

What is changed and how it works?

Moved the struct Pos from parser/lexer.go into parser/ast/ast.go

Added 2 methods

func (ast.node) SetOriginTextPos(ast.Pos) 
func (ast.node) OriginTextPos() ast.Pos

to the interface ast.Node

Check List

Tests

• Unit test

Code changes

• Has exported function/method change

Side effects

• Possible performance regression
• Breaking backward compatibility

Related changes

N/A

[tangenta]

Hi @TeemoKill, would you like to explain why we need this feature? Did you encounter any problems?

[ti-chi-bot]

@TeemoKill: PR needs rebase.

Details

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