fix: PC0037 CodeFix no longer fabricates semicolon before else

[Arthurvdv]

Problem

The PC0037 (UseValidateForFieldAssignment) CodeFix always fabricated a SemicolonToken when rewriting Rec.Field := Value into Rec.Validate(Field, Value). AL forbids a semicolon on a statement directly before else, so applying the fix to a then-branch assignment produced non-compiling code:

if BankImpExpMgtSAK.IsIBAN(IBANOrDesription) then
    Bankstatementline.Validate(IBAN, ...);  // <- illegal semicolon
else begin
end;

Although #395 was reported against the workspace Fix All, the semicolon was fabricated unconditionally, so single-instance fixes broke too.

Fix

Reuse the original assignment.SemicolonToken (a missing token when the assignment has none) instead of constructing a fresh one. Same pattern already used in GlobalLanguageImplementTranslationHelper.cs.

Tests

Two new HasFix regression cases (verified to fail against the unfixed CodeFix):

• IfElseNoSemicolon — issue repro: assignment as then-branch of if ... then ... else begin end;
• NestedIfElseInRepeatUntil — then-branch assignment before else inside repeat ... until

Full PlatformCop suite: 476/476 passing.

Follow-up

#398 tracks auditing the other CodeFixes that fabricate semicolon tokens.

Fixes #395