C++: Fix IR construction for implicit conversions in new initializers

[MathiasVP]

What the title says 😂

[Copilot]

Pull Request Overview

This PR fixes IR construction for implicit conversions in new initializers by ensuring that type conversions are properly handled when constructing the intermediate representation for new expressions with initializers.

• Uses the fully converted expression instead of the raw initializer for new expressions
• Adds test cases to verify proper IR generation for allocation with initializers requiring type conversion

Reviewed Changes

Copilot reviewed 5 out of 5 changed files in this pull request and generated no comments.

Show a summary per file

File	Description
cpp/ql/lib/semmle/code/cpp/ir/implementation/raw/internal/TranslatedExpr.qll	Modified to use getFullyConverted() on the initializer expression
cpp/ql/test/library-tests/ir/ir/ir.cpp	Added test function with new expressions requiring implicit conversions
cpp/ql/test/library-tests/ir/ir/raw_ir.expected	Updated expected IR output for the new test cases
cpp/ql/test/library-tests/ir/ir/aliased_ir.expected	Updated expected aliased IR output for the new test cases
cpp/ql/test/library-tests/ir/ir/PrintAST.expected	Updated expected AST output showing the implicit conversion

[jketema]

LGTM

[MathiasVP]

DCA was uneventful