Fill Document.id when building the Document from a search

[sergiocharpineljr]

When retrivieing documents through one of the search methods, the Document.id attribute is not being set. This PR attempts to fix it by properly filling the id attribute.

Before:

>>> vector_store.similarity_search("DRP")[0].id
>>> 

After:

>>> new_vector_store.similarity_search("DRP")[0].id
'ae34ea90-8c48-4990-8a81-6835cb9a021b'
>>>