Do not use cached entities in code generation

[andrewnester]

Changes

Code generator stores the defined types (entities) in pkg.types field. This field is primarily used for keeping the list of all observed types while generating code.

But if we use the entity stored in this map and modify it in-place, for example, add that some field is required, it will change the entity stored.

If later one we use this "cached" version of entity, it will contain modified configuration which can lead to unexpected results, for example, User entity in Users.create operation will have ID field as required even though based on OpenAPI definition it is not.

Thus, it's better not to use cached entities.

Tests

• make test passing
• make fmt applied

[codecov-commenter]

Codecov Report

Patch coverage: 100.00% and project coverage change: -0.04 ⚠️

Comparison is base (d722c3c) 19.15% compared to head (ac19341) 19.11%.

Additional details and impacted files

@@            Coverage Diff             @@
##             main     #403      +/-   ##
==========================================
- Coverage   19.15%   19.11%   -0.04%     
==========================================
  Files          82       82              
  Lines        8683     8679       -4     
==========================================
- Hits         1663     1659       -4     
  Misses       6874     6874              
  Partials      146      146              

Impacted Files	Coverage Δ
openapi/code/package.go	58.12% <100.00%> (-0.81%)	⬇️

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[pietern]

For my info, where are these entities modified after being returned?

[andrewnester]

@pietern as an example, for Users.* operation we were returning cached object here https://github.com/databricks/databricks-sdk-go/blob/main/openapi/code/service.go#L139

It happens that Users.update and such are processed before Users.create operation in code generator.

When we process Users.update, request object was modified here
https://github.com/databricks/databricks-sdk-go/blob/main/openapi/code/service.go#L172

Thus, when Users.create is processed and takes request schema from cache, it contains wrong required fields.

[nfx]

this PR breaks SDK generation with path parameters