[Compiler] Add tests for compiling casting expressions to casting instructions

[turbolent]

Depends on #3767
Work towards #3742

Description

Also add some test cases just for compiling the expressions to instructions.

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• Targeted PR against master branch
• Linked to Github issue with discussion and accepted design OR link to spec that describes this work
• Code follows the standards mentioned here
• Updated relevant documentation
• Re-reviewed Files changed in the Github PR explorer
• Added appropriate labels

[SupunS]

Thank you for adding this 🙌

[github-actions]

Cadence Benchstat comparison

This branch with compared with the base branch onflow:feature/compiler commit 63c1541
The command for i in {1..N}; do go test ./... -run=XXX -bench=. -benchmem -shuffle=on; done was used.
Bench tests were run a total of 7 times on each branch.

Collapsed results for better readability