feat(preset/client): allow use of enumsAsConst config option

[Stephen2]

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Description

Allows 'enumsAsConst' option to be used with client preset. Extremely simple and safe. Based on requests here: https://github.com/dotansimha/graphql-code-generator/issues/8562

Related # (issue)

https://github.com/dotansimha/graphql-code-generator/issues/8562

Type of change

• [x] New feature (non-breaking change which adds functionality)

How Has This Been Tested?

Tested on my local project, with a complex GraphQL schema, generating 2 types (masked & unmasked):

graphql.config.ts excerpt:

            generates: {
                'src/gql/': {
                    preset: 'client',
                    plugins: [],
                    config: {
                        // To generate string unions, instead of Enum, so backend <> frontend doesn't need conversion
                        enumsAsConst: true
                    },
                    presetConfig: {
                        fragmentMasking: {
                            unmaskFunctionName: 'getFragmentData'
                        }
                    }
                },

                // Backend server just returns the full shape of objects, and always has to return __typename or Apollo gets lost
                'src/gql/__backend__/': {
                    preset: 'client',
                    plugins: ['typescript-msw'],
                    config: {
                        nonOptionalTypename: true,

                        namingConvention: {
                            typeNames: './backend-gql-naming-fn'
                        },

                        // To generate string unions, instead of Enum, so backend <> frontend doesn't need conversion
                        enumsAsConst: true
                    },
                    presetConfig: {
                        fragmentMasking: false
                    }
                }
            }

Test Environment:

• OS: MacOS 13.5 (22G74)
• @graphql-codegen/...:

        "@graphql-codegen/cli": "4.0.1",
        "@graphql-codegen/client-preset": "4.0.1",
        "@graphql-codegen/typescript-msw": "^1.1.6",

• NodeJS:

❯ node -v && npm -v
v16.20.1
8.19.4

Checklist:

• [x] I have followed the CONTRIBUTING doc and the style guidelines of this project
• [x] I have performed a self-review of my own code
• [ ] I have commented my code, particularly in hard-to-understand areas
• [ ] I have made corresponding changes to the documentation
• [x] My changes generate no new warnings
• [ ] I have added tests that prove my fix is effective or that my feature works
• [x] New and existing unit tests pass locally with my changes
• [ ] Any dependent changes have been merged and published in downstream modules

[changeset-bot[bot]]

🦋 Changeset detected

Latest commit: 70eb250278551cdae060cad75bf800f01a6adf80

The changes in this PR will be included in the next version bump.

This PR includes changesets to release 1 package

Name	Type
@graphql-codegen/client-preset	Minor

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[Stephen2]

Force pushed, to keep up to date. Any maintainer willing to engage with this PR? 🙏

[mvestergaard]

@dylan-oleria Can this be merged please? We have functionality dependant on enumsAsConst, so can't use client preset currently.