FRC-0104: add ChainGetFinalizedTipSet (#1199)

* FRC-0104: add ChainGetFinalizedTipSet

Adds `ChainGetFinalizedTipSet` given it's addition to Lotuvs `/v1` in filecoin-project/lotus#13299

* Update FRCs/frc-0104.md

Co-authored-by: Alexey Krasnoperov <[email protected]>

* Update common-node-api.json

---------

Co-authored-by: Alexey Krasnoperov <[email protected]>

Author: BigLep

FRCs/frc-0104.md

@@ -76,6 +76,7 @@ methods beyond what is included in this specification.
 | ChainGetBlock                       | State query      | Returns the block with the specified CID.                                                                                                                                                      |
 | ChainGetBlockMessages               | State query      | Returns all messages from the specified block.                                                                                                                                                 |
 | ChainGetEvents                      | State query      | Returns the events under the given event AMT root CID.                                                                                                                                         |
+| ChainGetFinalizedTipSet             | State query      | Returns the latest F3 finalized tipset, or falls back to EC finality if F3 is not operational on the node or if the F3 finalized tipset is further back than EC finalized tipset.                                                                                                                                         |
 | ChainGetMessage                     | State query      | Returns the message with the specified CID.                                                                                                                                                    |
 | ChainGetParentMessages              | State query      | Returns the messages included in the blocks of the parent tipset.                                                                                                                              |
 | ChainGetParentReceipts              | State query      | Returns the message receipts included in the blocks of the parent tipset.                                                                                                                      |