go: Remove the integrated ledger support

[Yawning]

This has been moved to a separate repository.

Note: Yes this updates a bunch of dependencies. The build got super mad when I messed with go.mod.

[codecov]

Codecov Report

Merging #3128 into master will increase coverage by 0.52%.
The diff coverage is n/a.

@@            Coverage Diff             @@
##           master    #3128      +/-   ##
==========================================
+ Coverage   68.42%   68.95%   +0.52%     
==========================================
  Files         376      373       -3     
  Lines       37065    36986      -79     
==========================================
+ Hits        25363    25504     +141     
+ Misses       8451     8258     -193     
+ Partials     3251     3224      -27     

Impacted Files	Coverage Δ
go/oasis-node/cmd/common/signer/signer.go	57.31% <ø> (+4.62%)	⬆️
go/oasis-node/cmd/signer/signer.go	26.31% <ø> (-12.82%)	⬇️
go/consensus/tendermint/api/errors.go	86.66% <0.00%> (-13.34%)	⬇️
go/worker/compute/executor/committee/state.go	74.07% <0.00%> (-11.12%)	⬇️
...sensus/tendermint/epochtime_mock/epochtime_mock.go	70.63% <0.00%> (-5.56%)	⬇️
go/worker/compute/executor/committee/node.go	61.58% <0.00%> (-4.90%)	⬇️
.../consensus/tendermint/apps/epochtime_mock/state.go	74.46% <0.00%> (-4.26%)	⬇️
go/worker/common/committee/node.go	72.88% <0.00%> (-2.83%)	⬇️
go/worker/compute/merge/committee/node.go	75.54% <0.00%> (-0.73%)	⬇️
go/consensus/tendermint/services.go	82.81% <0.00%> (ø)
... and 32 more

---

Continue to review full report at Codecov.

Legend - Click here to learn more
Δ = absolute <relative> (impact), ø = not affected, ? = missing data
Powered by Codecov. Last update f7a4d38...6602212. Read the comment docs.