fix(cli)!: protect client Logger and refactor cli scaletest tests (#8317)

- (breaking) Protects Logger and LogBodies fields of codersdk.Client with its mutex. This addresses a data race in cli/scaletest.
- Fillets the existing cli/createworkspaces unit test and moves the testing logic there into the tests under scaletest/createworkspaces.
- Adds testutil.RaceEnabled bool const and conditionaly skips previously-skipped tests under scaletest/ if the race detector is enabled. This is unfortunate and sad, but I would prefer to have these tests at least running without the race detector than not running at all.
- Adds IgnoreErrors option to fake in-memory agent loggers; having the agents fail the test immediately when they encounter any sort of error isn't really helpful.

cli/ssh.go

@@ -119,7 +119,7 @@ func (r *RootCmd) ssh() *clibase.Cmd {
 				}
 
 				// log HTTP requests
-				client.Logger = logger
+				client.SetLogger(logger)
 			}
 
 			workspace, workspaceAgent, err := getWorkspaceAndAgent(ctx, inv, client, codersdk.Me, inv.Args[0])