feat: support = operator in function args

[universalmind303]

closes #1057

[alamb]

Thank you for the contribution @universalmind303 -- this looks great to me

[alamb]

Suggested change

	/// Operator used to separate function arguments
	/// Operator used to separate named function arguments

[coveralls]

Pull Request Test Coverage Report for Build 7838313913

• -3 of 45 (93.33%) changed or added relevant lines in 3 files are covered.
• No unchanged relevant lines lost coverage.
• Overall coverage increased (+0.01%) to 87.675%

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Changes Missing Coverage	Covered Lines	Changed/Added Lines	%
src/ast/mod.rs	8	9	88.89%
src/parser/mod.rs	10	12	83.33%

Totals
Change from base Build 7838299826:	0.01%
Covered Lines:	19612
Relevant Lines:	22369

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💛 - Coveralls

[alamb]

I think the CI check is failing due to the new Rust version that was released recently. I will fix that

[alamb]

I merged up from main to pick up #1130