Bugfix/zero number literal initialization

[lanarimarco]

Description

If the rpg code contains 0 formatted as 0000 or 00.00, the precision of such constants, computed through IntLiteral or RealLiteral, is always 1.

This behavior is due to the fact that:

• for the integer constant: "0000".toLong() is 0 and the precision is 1
• for the real constant: BigDecimal("00.00") has precision 1 and scale 2

While the first case was (more on less) predictable, the second one, honestly was not.

However, to fix this issue I have added property precision both for IntLiteral and RealLiteral and lightly changed the Expression.type() implementation.

This fix is necessary because Expression.type() is vital in the EDITC fixing which is in work in progress.

Checklist:

• There are tests regarding this feature
• The code follows the Kotlin conventions (run ./gradlew ktlintCheck)
• The code passes all tests (run ./gradlew check)
• There is a specific documentation in the docs directory

[lanarimarco]

@cosentino-smeup I have assigned you the code review because you are facing the editc issue, let me know if you need further support.

[cosentino-smeup]

Perfect. I am going to test it thoroughly when I will merge these changes in the branch "bugfix/NW23001440/EDITC_problems" because I'll have a wider number of user cases.