fix: allow to use custom openapi file

[wtrocki]

Proposed changes

For exception management I have been manually copying downstream PR's openAPI so far. This PR automates it so you can automatically refresh exceptions based on new openapi changes.

Example:

 npm run ipa-filter-violations xgen-IPA-102-collection-identifier-camelCase https://raw.githubusercontent.com/mongodb/openapi/refs/heads/dev/openapi/.raw/v2.yaml

Example for fixed issues (verification of exception PR):

npm run ipa-filter-violations xgen-IPA-108-delete-response-should-be-empty https://raw.githubusercontent.com/mongodb/openapi/refs/heads/dev/openapi/.raw/v2.yaml 

> ipa-filter-violations
> node tools/spectral/ipa/scripts/filter-ipa-violations.js xgen-IPA-108-delete-response-should-be-empty https://raw.githubusercontent.com/mongodb/openapi/refs/heads/dev/openapi/.raw/v2.yaml

Filtering violations for rule ID: xgen-IPA-108-delete-response-should-be-empty
Running IPA validation...
Using remote OpenAPI file: xxx
Downloading OpenAPI file from xxx
Download complete
(node:35488) [DEP0040] DeprecationWarning: The `punycode` module is deprecated. Please use a userland alternative instead.
(Use `node --trace-deprecation ...` to show where the warning was created)
Filtering results...
Results saved to/openapi/xgen-IPA-108-delete-response-should-be-empty-violations.md
Found 0 violations to fix
....
Results saved to /Users/w.trocki/Projects/sandbox/openapi/xgen-IPA-108-delete-request-no-body-violations.md
Found 0 violations to fix