[v1.14] Add composite embedders and pooling for huggingface embedders (experimental)

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This issue follows the changes related to Meilisearch v1.14.0 [mega issue](https://github.com/meilisearch/integration-guides/issues/315).

## Description

Update embedders API to be compatible with Meilisearch v1.14.0

For more context, see the related issue in Meilisearch: https://github.com/meilisearch/meilisearch/issues/5343

## Tasks

- [ ] Add new `pooling` parameter for `huggingFace` embedders
- [ ] Add new `composite` source for embedders

For reference, here's how this works using [Meilisearch JS SDK](https://github.com/meilisearch/meilisearch-js):

```ts
client
.index('index_name')
.updateEmbedders({
embedder_name: {
source: "composite",
searchEmbedder: {
source: "huggingFace",
model:
"sentence-transformers/paraphrase-multilingual-MiniLM-L12-v2",
pooling: "useModel",
},
indexingEmbedder: {
source: "huggingFace",
model:
"sentence-transformers/paraphrase-multilingual-MiniLM-L12-v2",
documentTemplate: "{{doc.title}}",
pooling: "useModel",
documentTemplateMaxBytes: 500,
},
},
});
```

Start at the Java client's updateEmbedders API and compare its supported embedder configuration with the Meilisearch JS SDK example. Review the linked Meilisearch v1.14 and issue #5343 references; done means supporting the huggingFace pooling parameter and composite source, including the shown nested configuration.

Written by the indexing model from the issue text.