[serve] Add multi-app support to serve deploy

[zcin]

Why are these changes needed?

Updated serve deploy to accept both

• The original ServeApplicationSchema for deploying a single application
• The new ServeDeploySchema for deploying multiple applications

Details:

• ServeApplicationSchema and ServeDeploySchema have different required fields, so there is no ambiguity - one config cannot be successfully parsed as both.
• If a config fails to parse as either of them, the validation error from trying to parse as ServeApplicationSchema will be surfaced.
• ServeDeploySchema will go through /api/serve/applications and ServeApplicationSchema will go through /api/serve/deployments

Related issue number

Checks

• I've signed off every commit(by using the -s flag, i.e., git commit -s) in this PR.
• I've run scripts/format.sh to lint the changes in this PR.
• I've included any doc changes needed for https://docs.ray.io/en/master/.
• I've made sure the tests are passing. Note that there might be a few flaky tests, see the recent failures at https://flakey-tests.ray.io/
• Testing Strategy
  • Unit tests
  • Release tests
  • This PR is not tested :(

[edoakes]

@zcin can we add a test for multiple apps with different runtime_envs?

[sihanwang41]

Hi Cindy, let's add some failure case in the unit tests:

• Same app name.
• Same route_prefix.
• One application failed to deploy and the other one is good.

[zcin]

@zcin can we add a test for multiple apps with different runtime_envs?

@edoakes Added! I added a test at the python API level instead of adding it as a cli test.

Hi Cindy, let's add some failure case in the unit tests:

• Same app name.
• Same route_prefix.
• One application failed to deploy and the other one is good.

@sihanwang41 I added a unit test for one app that succeeds and one that fails (also a python API test instead of cli test). For the other two, I believe those should be Pydantic validation errors after this PR is merged.

[sihanwang41]

@zcin can we add a test for multiple apps with different runtime_envs?

@edoakes Added! I added a test at the python API level instead of adding it as a cli test.

Hi Cindy, let's add some failure case in the unit tests:

• Same app name.
• Same route_prefix.
• One application failed to deploy and the other one is good.

@sihanwang41 I added a unit test for one app that succeeds and one that fails (also a python API test instead of cli test). For the other two, I believe those should be Pydantic validation errors after this PR is merged.

For the REST/CLI perspective, let's add those tests and assert validation errors always happening ? :) (make sure we show the error message clearly to the caller )

[zcin]

For the REST/CLI perspective, let's add those tests and assert validation errors always happening ? :) (make sure we show the error message clearly to the caller )

Sounds good, I'll add those after #32787 is merged.

[zcin]

@sihanwang41 Added tests for conflicting app name and conflicting route prefix.

[zcin]

@edoakes ready for merge?