Add method to define path for specific endpoint

[vincentsarago]

Right now when using Factories we create endpoints with predefined paths

titiler/src/titiler/core/titiler/core/factory.py

Lines 437 to 441 in 962dc60

	@self.router.get(r"/tiles/{z}/{x}/{y}", **img_endpoint_params)
	@self.router.get(r"/tiles/{z}/{x}/{y}.{format}", **img_endpoint_params)
	@self.router.get(r"/tiles/{z}/{x}/{y}@{scale}x", **img_endpoint_params)
	@self.router.get(r"/tiles/{z}/{x}/{y}@{scale}x.{format}", **img_endpoint_params)
	@self.router.get(r"/tiles/{TileMatrixSetId}/{z}/{x}/{y}", **img_endpoint_params)

Sometimes users would want a different schema (e.g no optional format in path or TileMatrixSet 🤷‍♂️)

The only example I know is stac-fastapi https://github.com/stac-utils/stac-fastapi/blob/06f610e74ca5eb1b28756ce66b508d5f974dd559/stac_fastapi/api/stac_fastapi/api/app.py#L172-L183

[vincentsarago]

note: in some ways I've been able to add path parameter to all endpoint within a Factory by adding prefix with {value}

https://github.com/stac-utils/titiler-pgstac/blob/b510490d0fc5764474493e206884773592a42f53/titiler/pgstac/main.py#L87-L95