fix: coderd: decouple ttl and deadline (#2282)

This commit makes the following changes:

- Partially reverts the changes of feat: update workspace deadline when workspace ttl updated #2165, making the deadline of a running workspace build independant of TTL, once started.
- CLI: updating a workspace TTL no longer updates the deadline of the workspace.
- UI: updating a workspace TTL no longer updates the deadline of the workspace.
- Drive-by: API: When creating a workspace, default TTL to min(12 hours, template max_ttl) if not instructed otherwise.
- Drive-by: CLI: list: measure workspace extension correctly (+X in last column) from the time the provisioner job was completed
- Drive-by: WorkspaceSchedule: show timezone of schedule if it is set, defaulting to dayjs guess otherwise.
- Drive-by: WorkspaceScheduleForm: fixed an issue where deleting the "TTL" value in the form would show the text "Your workspace will shut down a few seconds after start".

cli/ttl_test.go

@@ -3,7 +3,6 @@ package cli_test
 import (
 	"bytes"
 	"context"
-	"fmt"
 	"strings"
 	"testing"
 	"time"
@@ -109,9 +108,6 @@ func TestTTL(t *testing.T) {
 			assert.NoError(t, err, "unexpected error")
 		}()
 
-		pty.ExpectMatch(fmt.Sprintf("warning: ttl rounded down to %s", ttl.Truncate(time.Minute)))
-		pty.ExpectMatch(fmt.Sprintf("Workspace %q will be stopped in 8h29m0s. Are you sure?", workspace.Name))
-		pty.WriteLine("yes")
 		// Ensure ttl updated
 		updated, err := client.Workspace(ctx, workspace.ID)
 		require.NoError(t, err, "fetch updated workspace")