cmd/dolt/commands/sqlserver: Restructure the start up sequence for sql-server.

[reltuk]

We explicitly model Services, which can have an Init step, a Run step and a Stop step. Every registered service get initialized in the order they were registered in, then they all run concurrently until Stop is called, when they all get Stopped in reverse order. It's possible for clients to wait for init to be completed and be delivered any errors encountered on startup. They can also wait for stop, to be delivered any errors encountered on shutdown.

[zachmu]

So overall I think there's a good abstraction here, but I'm not wild about the current implementation details. Basically boils down to 3 big points:

1. There's leakage from one service's Init to another, e.g. clusterController gets Init'ed by one service then used by the Init of another one. These things should be reasonably self-contained
2. There are many Init-only "Services", which is another sign of a leaky abstraction. A thing that just runs an Init block and doesn't even need the cleanup of Close() isn't a service and shouldn't be modeled as one
3. The actual services should be better encapsulated with their own types and probably their own files, not just anonymous functions. Service should probably be an interface, not a struct with funcs.

Basically I think you need to do a better job modeling and separating the concerns of initialization from the concerns of running a service and cleaning up when it shuts down.

[reltuk]

I moved Service to an interface but I ended up leaving all the existing uses as instances of a struct implementation. When I teased things apart a bit further, if felt like I was getting less readable code, à la http://number-none.com/blow/john_carmack_on_inlined_code.html ...which, to be fair, we do have some gross mutations in here.

[github-actions]

@coffeegoddd DOLT

test_name	detail	row_cnt	sorted	mysql_time	sql_mult	cli_mult
batching	LOAD DATA	10000	1	0.05	0.6
batching	batch sql	10000	1	0.08	1.25
batching	by line sql	10000	1	0.08	1.25
blob	1 blob	200000	1	0.89	3.09	3.54
blob	2 blobs	200000	1	0.85	4.14	4.74
blob	no blob	200000	1	0.86	1.35	1.44
col type	datetime	200000	1	0.81	1.8	1.93
col type	varchar	200000	1	0.68	1.82	1.9
config width	2 cols	200000	1	0.79	1.41	1.28
config width	32 cols	200000	1	1.84	1.53	2.49
config width	8 cols	200000	1	0.93	1.44	1.66
pk type	float	200000	1	0.84	1.26	1.26
pk type	int	200000	1	0.78	1.27	1.31
pk type	varchar	200000	1	1.51	1.01	0.99
row count	1.6mm	1600000	1	5.6	1.5	1.53
row count	400k	400000	1	1.38	1.46	1.49
row count	800k	800000	1	2.84	1.47	1.48
secondary index	four index	200000	1	3.59	1.08	0.91
secondary index	no secondary	200000	1	0.86	1.35	1.42
secondary index	one index	200000	1	1.12	1.49	1.45
secondary index	two index	200000	1	1.99	1.2	1.09
sorting	shuffled 1mm	1000000	0	5.03	1.84	1.82
sorting	sorted 1mm	1000000	1	5.07	1.84	1.81

[github-actions]

@coffeegoddd DOLT

name	detail	mean_mult
dolt_blame_basic	system table	1.21
dolt_blame_commit_filter	system table	2.72
dolt_commit_ancestors_commit_filter	system table	0.87
dolt_commits_commit_filter	system table	0.97
dolt_diff_log_join_from_commit	system table	1.61
dolt_diff_log_join_to_commit	system table	1.61
dolt_diff_table_from_commit_filter	system table	1.06
dolt_diff_table_to_commit_filter	system table	1.13
dolt_diffs_commit_filter	system table	1
dolt_history_commit_filter	system table	1.23
dolt_log_commit_filter	system table	0.93