* get_signatures_for_address does not correctly account for result sets that span Blockstore and Bigtable.
This causes Bigtable to return `RowNotFound` until the new tx is uploaded.
Check that `before` exists in Bigtable, and if not, set it to `None` to return the full data set.
References #21442
Closes #22110
* Differentiate between before sig not found and no newer signatures
* Dedupe bigtable results to account for potential upload race
Co-authored-by: Tyera Eulberg <tyera@solana.com>
(cherry picked from commit bac6821e19
)
Co-authored-by: Omar Kilani <omar.kilani@gmail.com>