Should `ConstValue` add new constructor from bool ?

I find that struct field with default bool value , it will parse the value to Text.

Example:

```
struct Demo{
1: bool flag = false
}

```
It will generate `fieldDefaultValue` with the `ConstLiteral Text srcAnnot`. I think `ConstValue` should add `ConstBool Bool srcAnnot` constructor.

Look at the ConstValue type definition in the parser, likely in a module like Language.Thrift.Syntax. Add a ConstBool constructor. Update the parser logic for default values in struct fields to generate this new constructor for boolean literals. Run existing tests to ensure no regressions and add a test for the new behavior.

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