Summary:
Previously, when a table rewrite DDL operation (such as `ALTER COLUMN TYPE`, `ADD/DROP PRIMARY KEY` or `TRUNCATE TABLE`) was performed before creating a replication slot, the changes from that table were not streamed during logical replication.

The issue arose from the inconsistent handling of DocDB's UUID for a table's ID and PG’s `table_oid`. Normally, the table’s UUID in DocDB matches the `table_oid` in PG. However, in the case of table rewrites, while PG’s `table_oid` remains the same, the DocDB UUID changes. After such rewrites, the `relfilenode` in PG becomes the one-to-one mapping to the new UUID in DocDB (commit: bb77fb2052ad259457b01c586dc96075ad88b958).

For clarity, the following terminology will be used throughout this summary:
 - `table_id`: Refers to the UUID of the underlying DocDB table.
 - `pg_table_id`: Refers to the original UUID of the DocDB table before the table rewrite.
 - `table_oid`: Represents PG’s table OID.
 - `relfilenode`: Corresponds to the relfilenode of the PG table, which maps to DocDB’s UUID.

It’s important to note that without any table rewrites, `table_oid` is equal to `relfilenode`. However, with table rewrites, `relfilenode` reflects the new underlying table, while `table_oid` remains unchanged.

The following key changes were made to address the issue in this revision:
 1. In `YBCInitVirtualWalForCDC`, `table_id` is now computed using `relfilenode` instead of `table_oid` to ensure the correct `table_id` is passed to CDC Service.

 2. The `GetConsistentChanges` response now treats the `table_id` as `relfilenode` and accurately retrieves `table_oid` to be used within PG. Previously, `table_id` was directly treated as `table_oid`, causing inconsistencies.

 3. Similarly, when fetching the `replica_identity_map` (which maps table_id to its replica identity), the `table_id` was previously used directly to obtain the `table_oid`. Now, it is treated as `relfilenode`, and the `table_oid` is retrieved accordingly.

JIRA: DB-12672

Test Plan:
== Automated Testing ==
./yb_build.sh --java-test org.yb.pgsql.TestPgReplicationSlot#testWithAlterType
./yb_build.sh --java-test org.yb.pgsql.TestPgReplicationSlot#testWithDropAddPk
./yb_build.sh --java-test org.yb.pgsql.TestPgReplicationSlot#testWithTruncate

Reviewers: skumar, sumukh.phalgaonkar, stiwary, siddharth.shah, asrinivasan, xCluster, hsunder

Reviewed By: skumar, stiwary

Subscribers: yql, ybase, ycdcxcluster

Differential Revision: https://phorge.dev.yugabyte.com/D37721