feat(cli): implement ssh remote forward (#8515)

cli/testdata/coder_--help.golden

@@ -21,7 +21,9 @@ Coder v0.0.0-devel — A tool for provisioning self-hosted development environme
     logout            Unauthenticate your local session
     netcheck          Print network debug information for DERP and STUN
     ping              Ping a workspace
-    port-forward      Forward ports from machine to a workspace
+    port-forward      Forward ports from a workspace to the local machine.
+                      Forward ports from a workspace to the local machine. For
+                      reverse port forwarding, use "coder ssh -R".
     publickey         Output your Coder public key used for Git operations
     rename            Rename a workspace
     reset-password    Directly connect to the database to reset a user's

cli/testdata/coder_port-forward_--help.golden

@@ -1,6 +1,7 @@
 Usage: coder port-forward [flags] <workspace>
 
-Forward ports from machine to a workspace
+Forward ports from a workspace to the local machine. Forward ports from a
+workspace to the local machine. For reverse port forwarding, use "coder ssh -R".
 
 Aliases: tunnel
 

cli/testdata/coder_ssh_--help.golden

@@ -27,6 +27,9 @@ Start a shell into a workspace
           behavior as non-blocking.
           DEPRECATED: Use --wait instead.
 
+  -R, --remote-forward string, $CODER_SSH_REMOTE_FORWARD
+          Enable remote port forwarding (remote_port:local_address:local_port).
+
       --stdio bool, $CODER_SSH_STDIO
           Specifies whether to emit SSH output over stdin/stdout.