chore: remove steps to parse CloudFormation templates

[RomainMuller]

Parse directly into the *ParseTree structures instead of going through serde_yaml::Value as an initial step. This replaces a bunch of Derive implementations of serde::Deserialize with hand-coded ones, and completely removes the build_resource_recursively function (in favor of directly parsing).

This is not the complete implementation of the refactor (it'd be too big), and instead of an initial pass that focuses specifically on the ResourceValue enum. It also refactored intrinsics into an IntrinsicFunction enum to make the semantics a little easier to track here, and also to consolidate the parsing logic in a separate location.

[codecov]

Codecov Report

Patch coverage: 75.09% and project coverage change: +3.02 🎉

Comparison is base (b0f7103) 44.45% compared to head (981f49b) 47.48%.

Additional details and impacted files

@@            Coverage Diff             @@
##             main     #120      +/-   ##
==========================================
+ Coverage   44.45%   47.48%   +3.02%     
==========================================
  Files          20       21       +1     
  Lines        2641     2622      -19     
==========================================
+ Hits         1174     1245      +71     
+ Misses       1467     1377      -90     

Impacted Files	Coverage Δ
src/ir/resources.rs	20.76% <0.00%> (+0.61%)	⬆️
src/parser/output.rs	8.06% <0.00%> (-0.42%)	⬇️
src/primitives/mod.rs	43.47% <25.00%> (-20.16%)	⬇️
src/parser/intrinsics.rs	95.23% <95.23%> (ø)
src/parser/resource.rs	94.24% <95.80%> (+12.67%)	⬆️
src/parser/condition.rs	7.46% <100.00%> (ø)

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