service: plumb contexts to all (most) threads (#7363)

This continues the push of plumbing contexts through tendermint. I
attempted to find all goroutines in the production code (non-test) and
made sure that these threads would exit when their contexts were
canceled, and I believe this PR does that.

libs/cli/helper.go

@@ -69,7 +69,10 @@ func RunCaptureWithArgs(cmd Executable, args []string, env map[string]string) (s
 			var buf bytes.Buffer
 			// io.Copy will end when we call reader.Close() below
 			io.Copy(&buf, reader) //nolint:errcheck //ignore error
-			stdC <- buf.String()
+			select {
+			case <-cmd.Context().Done():
+			case stdC <- buf.String():
+			}
 		}()
 		return &stdC
 	}

libs/cli/setup.go

@@ -1,6 +1,7 @@
 package cli
 
 import (
+	"context"
 	"fmt"
 	"os"
 	"path/filepath"
@@ -22,6 +23,7 @@ const (
 // wrap if desired before the test
 type Executable interface {
 	Execute() error
+	Context() context.Context
 }
 
 // PrepareBaseCmd is meant for tendermint and other servers