feat: shed: ItestD

[magik6k]

Proposed Changes

ItestD is a lotus-shed command which starts a local daemon, and gives you an env var, which can be passed into itests. When an itest runs with that env var set, ItestD will allow you to open a shell with lotus* commands pointed at the running integration test.

[codecov]

Codecov Report

Merging #8290 (231893a) into master (326a9b6) will decrease coverage by 0.06%.
The diff coverage is 8.82%.

@@            Coverage Diff             @@
##           master    #8290      +/-   ##
==========================================
- Coverage   40.53%   40.47%   -0.07%     
==========================================
  Files         675      677       +2     
  Lines       73527    73595      +68     
==========================================
- Hits        29805    29787      -18     
- Misses      38500    38580      +80     
- Partials     5222     5228       +6     

Impacted Files	Coverage Δ
cmd/lotus-shed/itestd.go	0.00% <0.00%> (ø)
cmd/lotus-shed/main.go	0.00% <0.00%> (ø)
itests/kit/itestd.go	30.76% <30.76%> (ø)
itests/kit/rpc.go	100.00% <100.00%> (ø)
chain/events/observer.go	71.64% <0.00%> (-6.72%)	⬇️
storage/wdpost_sched.go	77.45% <0.00%> (-3.93%)	⬇️
chain/stmgr/call.go	67.87% <0.00%> (-3.64%)	⬇️
miner/miner.go	55.08% <0.00%> (-2.96%)	⬇️
chain/events/events_height.go	68.90% <0.00%> (-2.53%)	⬇️
chain/sub/incoming.go	45.25% <0.00%> (-2.45%)	⬇️
... and 17 more