Improve handling of -short flag in tests (#9075)

As a small developer quality of life improvement, I found many individual unit tests that take longer than around a second to complete, and set them to skip when run under `go test -short`.

On my machine, the wall timings for tests (with `go test -count=1 ./...` and optionally `-short` and `-race`) are roughly:

- Long tests, no race detector: about 1m42s
- Short tests, no race detector: about 17s
- Long tests, race detector enabled: about 2m1s
- Short tests, race detector enabled: about 28s

This PR is split into many commits each touching a single package, with commit messages detailing the approximate timing change per package.

internal/consensus/byzantine_test.go

@@ -33,6 +33,10 @@ import (
 // Byzantine node sends two different prevotes (nil and blockID) to the same
 // validator.
 func TestByzantinePrevoteEquivocation(t *testing.T) {
+	if testing.Short() {
+		t.Skip("skipping test in short mode")
+	}
+
 	// empirically, this test either passes in <1s or hits some
 	// kind of deadlock and hit the larger timeout. This timeout
 	// can be extended a bunch if needed, but it's good to avoid

internal/consensus/reactor_test.go

@@ -779,6 +779,10 @@ func TestReactorRecordsVotesAndBlockParts(t *testing.T) {
 }
 
 func TestReactorVotingPowerChange(t *testing.T) {
+	if testing.Short() {
+		t.Skip("skipping test in short mode")
+	}
+
 	ctx, cancel := context.WithTimeout(context.Background(), time.Minute)
 	defer cancel()
 
@@ -885,6 +889,10 @@ func TestReactorVotingPowerChange(t *testing.T) {
 }
 
 func TestReactorValidatorSetChanges(t *testing.T) {
+	if testing.Short() {
+		t.Skip("skipping test in short mode")
+	}
+
 	ctx, cancel := context.WithTimeout(context.Background(), 2*time.Minute)
 	defer cancel()
 

internal/consensus/replay_test.go

@@ -118,6 +118,10 @@ func sendTxs(ctx context.Context, t *testing.T, cs *State) {
 
 // TestWALCrash uses crashing WAL to test we can recover from any WAL failure.
 func TestWALCrash(t *testing.T) {
+	if testing.Short() {
+		t.Skip("skipping test in short mode")
+	}
+
 	testCases := []struct {
 		name         string
 		initFn       func(dbm.DB, *State, context.Context)