Detect cyclic field definitions in struct dependency graph

[Narasimha1997]

What was wrong?

As stated by @Y-Nak in the issue #682

How was it fixed?

By adding struct_cycles as salsa cycle callback that throws an error when cycles are detected.

[codecov-commenter]

Codecov Report

Merging #704 (1b5a991) into master (4aa56e2) will decrease coverage by 0.07%.
The diff coverage is 100.00%.

@@            Coverage Diff             @@
##           master     #704      +/-   ##
==========================================
- Coverage   82.05%   81.98%   -0.08%     
==========================================
  Files         125      125              
  Lines       10876    10950      +74     
==========================================
+ Hits         8924     8977      +53     
- Misses       1952     1973      +21     

Impacted Files	Coverage Δ
crates/analyzer/src/db.rs	100.00% <ø> (ø)
crates/analyzer/src/db/queries/structs.rs	77.47% <100.00%> (+2.73%)	⬆️
crates/analyzer/src/namespace/items.rs	92.64% <100.00%> (+0.11%)	⬆️
crates/parser/src/grammar/functions.rs	88.40% <0.00%> (-2.12%)	⬇️
crates/yulgen/src/mappers/expressions.rs	88.65% <0.00%> (-2.11%)	⬇️
crates/parser/src/ast.rs	87.53% <0.00%> (-1.01%)	⬇️
crates/analyzer/src/context.rs	61.34% <0.00%> (-0.85%)	⬇️
crates/lowering/src/mappers/functions.rs	99.42% <0.00%> (+<0.01%)	⬆️
crates/test-utils/src/lib.rs	89.63% <0.00%> (+0.03%)	⬆️
crates/analyzer/src/traversal/expressions.rs	80.86% <0.00%> (+0.10%)	⬆️
... and 2 more

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[Y-Nak]

Thanks for opening the PR.
The implementation itself is perfect 💯

nits:

1. Could you add close #682 to the PR comment to close the issue automatically when the PR is merged?
2. Could you add newsfragments/682.bugfix.md to ensure the fix will be included in the next release note?

[Narasimha1997]

@Y-Nak
Yup, did the changes you suggested.

[Y-Nak]

Thanks so much!