feat: implemented filtering users by coding language (#1048)

* feat: implemented filtering users by coding language

* fix: fixed prettier warning

* fix: fixed prettier warnings

* test: created mock data and tests for filterByCodingLanguage

* feat: helper function for filtering users by coding languages

* chore: moved filterByCoding language logic

* fix: fixed warnings

* Delete frontend/app/src/people/utils/__tests__/__mockData__/users.ts

* Delete frontend/app/src/people/utils/__tests__/filterValidation.spec.ts

* fix: fixed prettier warnings