PgVectorEmbeddingStore: remove by ID

[nottyjay]

Change

Add search method in PgVectorEmbeddingStore
Add remove data method in the interface of EmbeddingStore
Add remove data method in PgVectorEmbeddingStore

Checklist

• I have added unit and integration tests for my change
• All unit and integration tests in the module I have added/changed are green
• All unit and integration tests in the core and main modules are green

Checklist for adding new embedding store integration

• I have added a {NameOfIntegration}EmbeddingStoreIT that extends from either EmbeddingStoreIT or EmbeddingStoreWithFilteringIT

[nottyjay]

@langchain4j
Add remove method to delete embedding data which stored in vector store.
Add search in PgVectorEmbeddingStore
I checked locally everything compiles and tests pass.

[langchain4j]

@nottyjay thanks a lot!
Please revert changes of formatting, it is imposible to review right now :(

[langchain4j]

Related issue: #301

[humcqc]

Hi @langchain4j , @nottyjay perhaps this should be done after #851 to avoid more conflicts.
@nottyjay perhaps you could implement it on top of this PR, or I can do it quickly after we merge #851