Feat/constants support

[chadsec1]

This pull request adds support for constants, and it also seperates the abstract syntax tree nodes defintions from the parser into its own "ast.rs" file(s)

It also includes more unit tests, and significantly improved existing tests. and separated the tests into their own file for maintaniability

And it includes misc bug fixes, mainly error messages in semantic phase, and some edge cases in parser.

[codacy-production]

Not up to standards ⛔

🟢 Issues 0 issues

Results:
0 new issues

View in Codacy

🟢 Metrics 1609 complexity · 1278 duplication

Metric	Results
Complexity	1609
Duplication	1278

View in Codacy

🔴 Coverage 64.64% diff coverage · -5.58% coverage variation

Metric	Results
Coverage variation	❌ -5.58% coverage variation (-1.00%)
Diff coverage	✅ 64.64% diff coverage

View coverage diff in Codacy

Coverage variation details

	Coverable lines	Covered lines	Coverage
Common ancestor commit (c0a5e11)	Report Missing	Report Missing	Report Missing
Head commit (dfc46de)	2355 (+606)	1984 (+413)	84.25% (-5.58%)

Coverage variation is the difference between the coverage for the head and common ancestor commits of the pull request branch: <coverage of head commit> - <coverage of common ancestor commit>

Diff coverage details

	Coverable lines	Covered lines	Diff coverage
Pull request (#7)	707	457	64.64%

Diff coverage is the percentage of lines that are covered by tests out of the coverable lines that the pull request added or modified: <covered lines added or modified>/<coverable lines added or modified> * 100%

¹ Codacy didn't receive coverage data for the commit, or there was an error processing the received data. Check your integration for errors and validate that your coverage setup is correct.

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[chadsec1]

LGTM (talking to myself lol)