(amazonaurora): merge amazon aurora vector stores

[maxtybar]

Describe the feature

1. Merge AmazonAuroraDefaultVectorStore with AmazonAuroraVectorStore.
2. Create fromExistingAuroraVectorStore() function allowing user to use existing Aurora as a vector DB.
3. Move models.ts in a dedicated foundation-models construct due to cross-dependencies (currently Amazon Aurora relies on models.ts which is in bedrock module and bedrock relies on amazonaurora). In the future this will also allow potential new vector stores to consume foundation-models construct without creating cross-dependencies with bedrock construct.

Use Case

To allow user bring their own Aurora db and avoid confusion having 2 similar constructs/classes.

Proposed Solution

No response

Other Information

No response

Acknowledgements

• [X] I may be able to implement this feature request
• [ ] This feature might incur a breaking change

[maxtybar]

Working on it.