feat(ml): support multiple urls (#14347)

* support multiple url

* update api

* styling

unnecessary `?.`

* update docs, make new url field go first

add load balancing section

* update tests

doc formatting

wording

wording

linting

* small styling

* `url` -> `urls`

* fix tests

* update docs

* make docusaurus happy

---------

Co-authored-by: Alex <alex.tran1502@gmail.com>

server/src/services/person.service.spec.ts

@@ -717,7 +717,7 @@ describe(PersonService.name, () => {
       assetMock.getByIds.mockResolvedValue([assetStub.image]);
       await sut.handleDetectFaces({ id: assetStub.image.id });
       expect(machineLearningMock.detectFaces).toHaveBeenCalledWith(
-        'http://immich-machine-learning:3003',
+        ['http://immich-machine-learning:3003'],
         '/uploads/user-id/thumbs/path.jpg',
         expect.objectContaining({ minScore: 0.7, modelName: 'buffalo_l' }),
       );