* feat: make flux controller limits configurable
A sample of the new config:
```
[flux-controller]
query-concurrency = 0
query-initial-memory-bytes = 0
query-max-memory-bytes = 0
total-max-memory-bytes = 0
query-queue-size = 0
```
Also use the prometheus metrics in debug/vars, here is a sample:
```
"query_control_all_active": {"name":"query_control_all_active","tags":null,"values":{"gauge":0}},
"query_control_all_duration_seconds": {"name":"query_control_all_duration_seconds","tags":null,"values":{"0.001":0,"0.005":0,"0.025":0,"0.125":0,"0.625":0,"15.625":2,"3.125":2,"count":2,"sum":2.9953034240000003}},
"query_control_compiling_active": {"name":"query_control_compiling_active","tags":null,"values":{"gauge":0}},
"query_control_compiling_duration_seconds": {"name":"query_control_compiling_duration_seconds","tags":null,"values":{"0.001":2,"0.005":2,"0.025":2,"0.125":2,"0.625":2,"15.625":2,"3.125":2,"count":2,"sum":0.0010411650000000001}},
"query_control_executing_active": {"name":"query_control_executing_active","tags":null,"values":{"gauge":0}},
"query_control_executing_duration_seconds": {"name":"query_control_executing_duration_seconds","tags":null,"values":{"0.001":0,"0.005":0,"0.025":0,"0.125":0,"0.625":0,"15.625":2,"3.125":2,"count":2,"sum":2.994032791}},
"query_control_memory_unused_bytes": {"name":"query_control_memory_unused_bytes","tags":null,"values":{"gauge":0}},
"query_control_queueing_active": {"name":"query_control_queueing_active","tags":null,"values":{"gauge":0}},
"query_control_queueing_duration_seconds": {"name":"query_control_queueing_duration_seconds","tags":null,"values":{"0.001":2,"0.005":2,"0.025":2,"0.125":2,"0.625":2,"15.625":2,"3.125":2,"count":2,"sum":0.000087963}},
"query_control_requests_total": {"name":"query_control_requests_total","tags":null,"values":{"counter":1}},
"query_control_requests_total:1": {"name":"query_control_requests_total","tags":null,"values":{"counter":1}}
```
* chore: update changelog
* fix: shorten metric names for query control
* fix: zaptest logger and goimports
* fix: races in the query controller
Previously some tests were failing due to logging after the end of the test.
f1aa051787