Merged PRs

dolt

5606: go/store/nbs: store.go: Conjoin if we need to when we add new table files to a manifest.
This allows us to avoid huge manifests with lots of table files when we run multiple full GCs over a period of time.
5600: sql: dolt_gc: Enable the dolt_gc stored procedure. Make dolt_gc safe to use.
In order to establish a safepoint, call dolt_gc() will cause other connections to disconnect and will leave the connection which called it in a perpetual error state.
5597: Bug fix: binlog replication no longer assumes there is a root user
The binlog replication applier needs to execute SQL statements that modify any database or table being replicated from the primary. We were previously assuming the root user existed and had the right permissions for this, but that is not always true (e.g. Hosted Dolt does not create a root user on Dolt DBs). Since we can't rely on an existing account with the right privileges for executing those replicated SQL statements, we now create a custom dolt-binlog-applier user that has super user privs and is locked, to disable logins.
This change fixes the correctness issue in #5592 – if a root user doesn't exist, binlog replication will still work correctly.
If this direction looks good, I'll add some deeper testing around this.

Read Tests	MySQL	Dolt	Multiple
covering_index_scan	1.96	2.71	1.4
groupby_scan	12.3	16.41	1.3
index_join	1.18	4.03	3.4
index_join_scan	1.14	2.03	1.8
index_scan	30.81	52.89	1.7
oltp_point_select	0.16	0.48	3.0
oltp_read_only	3.07	8.58	2.8
select_random_points	0.31	0.73	2.4
select_random_ranges	0.36	1.14	3.2
table_scan	30.81	53.85	1.7
types_table_scan	71.83	158.63	2.2
reads_mean_multiplier			2.3

Write Tests	MySQL	Dolt	Multiple
bulk_insert	0.001	0.001	1.0
oltp_delete_insert	4.82	5.57	1.2
oltp_insert	2.35	2.81	1.2
oltp_read_write	6.55	15.55	2.4
oltp_update_index	2.43	2.91	1.2
oltp_update_non_index	2.48	2.81	1.1
oltp_write_only	3.55	7.43	2.1
types_delete_insert	4.82	6.32	1.3
writes_mean_multiplier			1.4

Overall Mean Multiple	1.9