feat(coderd): add matched provisioner daemons information to more places (#15688)

- Refactors `checkProvisioners` into `db2sdk.MatchedProvisioners`
- Adds a separate RBAC subject just for reading provisioner daemons
- Adds matched provisioners information to additional endpoints relating to
  workspace builds and templates
-Updates existing unit tests for above endpoints
-Adds API endpoint for matched provisioners of template dry-run job
-Updates CLI to show warning when creating/starting/stopping/deleting
 workspaces for which no provisoners are available

---------

Co-authored-by: Danny Kopping <danny@coder.com>

cli/cliutil/provisionerwarn_test.go

@@ -0,0 +1,74 @@
+package cliutil_test
+
+import (
+	"strings"
+	"testing"
+
+	"github.com/stretchr/testify/require"
+
+	"github.com/coder/coder/v2/cli/cliutil"
+	"github.com/coder/coder/v2/codersdk"
+)
+
+func TestWarnMatchedProvisioners(t *testing.T) {
+	t.Parallel()
+
+	for _, tt := range []struct {
+		name   string
+		mp     *codersdk.MatchedProvisioners
+		job    codersdk.ProvisionerJob
+		expect string
+	}{
+		{
+			name: "no_match",
+			mp: &codersdk.MatchedProvisioners{
+				Count:     0,
+				Available: 0,
+			},
+			job: codersdk.ProvisionerJob{
+				Status: codersdk.ProvisionerJobPending,
+			},
+			expect: `there are no provisioners that accept the required tags`,
+		},
+		{
+			name: "no_available",
+			mp: &codersdk.MatchedProvisioners{
+				Count:     1,
+				Available: 0,
+			},
+			job: codersdk.ProvisionerJob{
+				Status: codersdk.ProvisionerJobPending,
+			},
+			expect: `Provisioners that accept the required tags have not responded for longer than expected`,
+		},
+		{
+			name: "match",
+			mp: &codersdk.MatchedProvisioners{
+				Count:     1,
+				Available: 1,
+			},
+			job: codersdk.ProvisionerJob{
+				Status: codersdk.ProvisionerJobPending,
+			},
+		},
+		{
+			name: "not_pending",
+			mp:   &codersdk.MatchedProvisioners{},
+			job: codersdk.ProvisionerJob{
+				Status: codersdk.ProvisionerJobRunning,
+			},
+		},
+	} {
+		tt := tt
+		t.Run(tt.name, func(t *testing.T) {
+			t.Parallel()
+			var w strings.Builder
+			cliutil.WarnMatchedProvisioners(&w, tt.mp, tt.job)
+			if tt.expect != "" {
+				require.Contains(t, w.String(), tt.expect)
+			} else {
+				require.Empty(t, w.String())
+			}
+		})
+	}
+}