asim: place generated output in two subfolders

Previously, we split different test modes into their own subfolders.  This
commit extends the same change to the generated folder, so that its outputs are
also placed into two subfolders. Note that these are only organizational clean
ups - tests were grouped and labeled based on their original purpose. Tests
under sma may still specify cfgs = (mma-only or mma-count) and vice-versa for
tests under mma.

Author: wenyihu6

pkg/kv/kvserver/asim/tests/datadriven_simulation_test.go

@@ -474,7 +474,7 @@ func TestDataDriven(t *testing.T) {
 					seed := int64(42)
 					duration := 30 * time.Minute
 					name := strings.TrimSuffix(filepath.Base(path), filepath.Ext(path))
-					plotDir := datapathutils.TestDataPath(t, "generated", name)
+					plotDir := datapathutils.TestDataPath(t, "generated", mode, name)
 					var rewrite bool
 					require.NoError(t, sniffarg.DoEnv("rewrite", &rewrite))
 					var cfgs []string    // configurations to run the simulation with

pkg/kv/kvserver/asim/tests/testdata/generated/.gitignore

@@ -6,7 +6,7 @@
 # Except this specific directory (relative to .gitignore)
 # Note that this intentionally does not include subdirectories (such as traces)
 # which are not deterministic.
-!rebalancing/**
+!sma/rebalancing/**
 **/traces
 # And the readme file.
 !README.md