Unify model and prop meta

[blast-hardcheese]

With a bit of doing, modelMetaType and propMetaImpl ended up being able to be unified. Both were nearly identical implementations, but stemmed from the fact that in swagger 2.0 days, model and prop were different type families. After OpenAPI unified them, this became possible.

[codecov]

Codecov Report

Merging #1359 (f65e284) into master (5a0b5e4) will increase coverage by 13.87%.
The diff coverage is 90.41%.

@@             Coverage Diff             @@
##           master    #1359       +/-   ##
===========================================
+ Coverage   66.81%   80.69%   +13.87%     
===========================================
  Files          79       79               
  Lines        5446     5423       -23     
  Branches      141      138        -3     
===========================================
+ Hits         3639     4376      +737     
+ Misses       1807     1047      -760     

Impacted Files	Coverage Δ
...ore/src/main/scala/dev/guardrail/SwaggerUtil.scala	79.14% <89.23%> (+1.60%)	⬆️
...a/dev/guardrail/generators/ProtocolGenerator.scala	90.30% <100.00%> (+2.71%)	⬆️
...enerators/scala/http4s/Http4sServerGenerator.scala	94.06% <100.00%> (+91.10%)	⬆️
...les/core/src/main/scala/dev/guardrail/Common.scala	98.92% <0.00%> (+2.15%)	⬆️
...re/src/main/scala/dev/guardrail/core/Tracker.scala	93.18% <0.00%> (+2.27%)	⬆️
...a/dev/guardrail/generators/LanguageParameter.scala	85.88% <0.00%> (+2.35%)	⬆️
...i/src/main/scala/dev/guardrail/cli/CLICommon.scala	61.84% <0.00%> (+2.63%)	⬆️
...ain/scala/dev/guardrail/core/extract/package.scala	94.11% <0.00%> (+5.88%)	⬆️
...rail/generators/scala/jackson/JacksonHelpers.scala	11.76% <0.00%> (+11.76%)	⬆️
... and 18 more

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