Add parser support for semicolons after annotation

[Scony]

Following GDScript will now parse correctly:

pass;var x;@export;@onready;;;var y : float;pass

func test():
       pass

This closes #54280

[AaronRecord]

Why is this useful exactly? Annotations can already be written on the same line as a statement without a semicolon

[Scony]

@LightningAA it just fixes the lack of consistency among newline/semicolon-separated statements

[Scony]

Also, it allows code such as:

@tool;var x

to parse correctly.

[Mickeon]

The PR is two years old and, at least at a glance, looks good to me. Although there are no merge conflicts, could you rebase this just in case?

[Scony]

The PR is two years old and, at least at a glance, looks good to me. Although there are no merge conflicts, could you rebase this just in case?

done