feat(agent): add container list handler (#16346)

Fixes https://github.com/coder/coder/issues/16268

- Adds `/api/v2/workspaceagents/:id/containers` coderd endpoint that allows listing containers
visible to the agent. Optional filtering by labels is supported.
- Adds go tools to the `coder-dylib` CI step so we can generate mocks if needed

coderd/util/maps/maps.go

@@ -0,0 +1,27 @@
+package maps
+
+import (
+	"sort"
+
+	"golang.org/x/exp/constraints"
+)
+
+// Subset returns true if all the keys of a are present
+// in b and have the same values.
+func Subset[T, U comparable](a, b map[T]U) bool {
+	for ka, va := range a {
+		if vb, ok := b[ka]; !ok || va != vb {
+			return false
+		}
+	}
+	return true
+}
+
+// SortedKeys returns the keys of m in sorted order.
+func SortedKeys[T constraints.Ordered](m map[T]any) (keys []T) {
+	for k := range m {
+		keys = append(keys, k)
+	}
+	sort.Slice(keys, func(i, j int) bool { return keys[i] < keys[j] })
+	return keys
+}

coderd/util/maps/maps_test.go

@@ -0,0 +1,64 @@
+package maps_test
+
+import (
+	"strconv"
+	"testing"
+
+	"github.com/coder/coder/v2/coderd/util/maps"
+)
+
+func TestSubset(t *testing.T) {
+	t.Parallel()
+
+	for idx, tc := range []struct {
+		a        map[string]string
+		b        map[string]string
+		expected bool
+	}{
+		{
+			a:        nil,
+			b:        nil,
+			expected: true,
+		},
+		{
+			a:        map[string]string{},
+			b:        map[string]string{},
+			expected: true,
+		},
+		{
+			a:        map[string]string{"a": "1", "b": "2"},
+			b:        map[string]string{"a": "1", "b": "2"},
+			expected: true,
+		},
+		{
+			a:        map[string]string{"a": "1", "b": "2"},
+			b:        map[string]string{"a": "1"},
+			expected: false,
+		},
+		{
+			a:        map[string]string{"a": "1"},
+			b:        map[string]string{"a": "1", "b": "2"},
+			expected: true,
+		},
+		{
+			a:        map[string]string{"a": "1", "b": "2"},
+			b:        map[string]string{},
+			expected: false,
+		},
+		{
+			a:        map[string]string{"a": "1", "b": "2"},
+			b:        map[string]string{"a": "1", "b": "3"},
+			expected: false,
+		},
+	} {
+		tc := tc
+		t.Run("#"+strconv.Itoa(idx), func(t *testing.T) {
+			t.Parallel()
+
+			actual := maps.Subset(tc.a, tc.b)
+			if actual != tc.expected {
+				t.Errorf("expected %v, got %v", tc.expected, actual)
+			}
+		})
+	}
+}