Oraclevs integration (#29723)

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- [ ] **PR title**: "package: description"
- Where "package" is whichever of langchain, community, core, etc. is
being modified. Use "docs: ..." for purely docs changes, "infra: ..."
for CI changes.
  - Example: "community: add foobar LLM"
  community: langchain_community/vectorstore/oraclevs.py


- [ ] **PR message**: ***Delete this entire checklist*** and replace
with
- **Description:** Refactored code to allow a connection or a connection
pool.
- **Issue:** Normally an idel connection is terminated by the server
side listener at timeout. A user thus has to re-instantiate the vector
store. The timeout in case of connection is not configurable. The
solution is to use a connection pool where a user can specify a user
defined timeout and the connections are managed by the pool.
    - **Dependencies:** None
    - **Twitter handle:** 


- [ ] **Add tests and docs**: This is not a new integration. A user can
pass either a connection or a connection pool. The determination of what
is passed is made at run time. Everything should work as before.

- [ ] **Lint and test**:  Already done.

Additional guidelines:
- Make sure optional dependencies are imported within a function.
- Please do not add dependencies to pyproject.toml files (even optional
ones) unless they are required for unit tests.
- Most PRs should not touch more than one package.
- Changes should be backwards compatible.
- If you are adding something to community, do not re-import it in
langchain.

If no one reviews your PR within a few days, please @-mention one of
baskaryan, efriis, eyurtsev, ccurme, vbarda, hwchase17.

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Co-authored-by: Erick Friis <[email protected]>