community[minor]: Add support for Upstash Vector (#20824)

## Description

Adding `UpstashVectorStore` to utilize [Upstash
Vector](https://upstash.com/docs/vector/overall/getstarted)!

#17012 was opened to add Upstash Vector to langchain but was closed to
wait for filtering. Now filtering is added to Upstash vector and we open
a new PR. Additionally, [embedding
feature](https://upstash.com/docs/vector/features/embeddingmodels) was
added and we add this to our vectorstore aswell.

## Dependencies

[upstash-vector](https://pypi.org/project/upstash-vector/) should be
installed to use `UpstashVectorStore`. Didn't update dependencies
because of [this comment in the previous
PR](https://github.com/langchain-ai/langchain/pull/17012#pullrequestreview-1876522450).

## Tests

Tests are added and they pass. Tests are naturally network bound since
Upstash Vector is offered through an API.

There was [a discussion in the previous PR about mocking the
unittests](https://github.com/langchain-ai/langchain/pull/17012#pullrequestreview-1891820567).
We didn't make changes to this end yet. We can update the tests if you
can explain how the tests should be mocked.

---------

Co-authored-by: ytkimirti <yusuftaha9@gmail.com>
Co-authored-by: Bagatur <22008038+baskaryan@users.noreply.github.com>
Co-authored-by: Bagatur <baskaryan@gmail.com>

libs/community/tests/unit_tests/vectorstores/test_imports.py

@@ -83,6 +83,7 @@ EXPECTED_ALL = [
     "TileDB",
     "TimescaleVector",
     "Typesense",
+    "UpstashVectorStore",
     "USearch",
     "VDMS",
     "Vald",

libs/community/tests/unit_tests/vectorstores/test_indexing_docs.py

@@ -85,6 +85,7 @@ def test_compatible_vectorstore_documentation() -> None:
         "TileDB",
         "TimescaleVector",
         "TencentVectorDB",
+        "UpstashVectorStore",
         "EcloudESVectorStore",
         "Vald",
         "VDMS",

libs/community/tests/unit_tests/vectorstores/test_public_api.py

@@ -77,6 +77,7 @@ _EXPECTED = [
     "Tigris",
     "TimescaleVector",
     "Typesense",
+    "UpstashVectorStore",
     "USearch",
     "Vald",
     "VDMS",