feat: support x-enumNames param for client code generations

[nadavhalfon]

Supporting numeric enums for client code generators

PR Checklist

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• The commit message follows our guidelines: https://github.com/nestjs/nest/blob/master/CONTRIBUTING.md
• Tests for the changes have been added (for bug fixes / features)
• Docs have been added / updated (for bug fixes / features)

PR Type

What kind of change does this PR introduce?

• Bugfix
• Feature
• Code style update (formatting, local variables)
• Refactoring (no functional changes, no api changes)
• Build related changes
• CI related changes
• Other... Please describe:

What is the current behavior?

When using a client swagger generator for numeric enums there is a missing feature for setting the enum names, causing a problem when needed to use a numeric enum without success, adding 'x-enumNames' with ts-ignore causing the param to not be copy to the component created when using 'enumName'

Issue Number: N/A

What is the new behavior?

When copying the params of the enum to the created component add also 'x-enumNames', and then the numeric enum will be generated fine using a codegen

Does this PR introduce a breaking change?

• Yes
• No

Other information

[kamilmysliwiec]

lgtm