API, API-CLIENT: Add `environmentSlug` in multiple places across the `variable` module

[rajdip-b]

Description

A lot of places in the variable module are sending environmentId in the response, when in reality we also want the environmentSlug. Add the field in the required places.

Solution

Here's a list of places that you would need to update.

• https://github.com/keyshade-xyz/keyshade/blob/1f864df4180f65c8f42f8984b6a014d44c366901/apps/api/src/variable/service/variable.service.ts#L121-L127
• https://github.com/keyshade-xyz/keyshade/blob/1f864df4180f65c8f42f8984b6a014d44c366901/apps/api/src/variable/service/variable.service.ts#L245-L249
• https://github.com/keyshade-xyz/keyshade/blob/1f864df4180f65c8f42f8984b6a014d44c366901/apps/api/src/variable/service/variable.service.ts#L489-L515
• https://github.com/keyshade-xyz/keyshade/blob/1f864df4180f65c8f42f8984b6a014d44c366901/apps/api/src/variable/service/variable.service.ts#L558-L580
• Update the tests in variable.e2e.spec.ts to display these changes.
• Update the types in api-client package under variable.ts
• Update the tests in api-cleint package under variable.spec.ts

[Nil2000]

/attempt

[github-actions[bot]]

Assigned the issue to @Nil2000!