Resolves Issues:
* https://github.com/hasura/graphql-engine-mono/issues/658 - Invalid Slashes
* https://github.com/hasura/graphql-engine-mono/issues/628 - Subscriptions
Implementation:
* Moved some logic from Endpoint.hs to allow reuse of splitting url into PathSegments.
* Additional validation steps alongside checking for overlapping routes
* Logging potential misuse of GET for mutations
Future Work:
* [ ] GET is allowed for mutations (Ignore/Log warning for Now)
* [ ] Add to scInconsistentObjs rather than throwing error
* Add information to scInconsistentObjs instead of raising errors directly.
TODO:
* [x] Duplicate variable segments with the same name in the location should not be allowed
* [x] We should throw an error on trailing and leading slashes and URLs which contain empty segments
* [x] Endpoints can be created using subscriptions. But the error only shows at the time of the query
* [x] Tests
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### Kodiak commit message
Prohibit Invalid slashes, duplicate variables, subscriptions for REST endpoints.
GitOrigin-RevId: 86c0d4af97984c8afd02699e6071e9c1658710b8
