feat: Rename config-ssh --diff to --dry-run (#2575)

* feat: Rename config-ssh `--diff` to `--dry-run`

Since the intent between diff and dry-run are different, this change
allows for interactive prompts to be shown during `--dry-run`,
previously prompts were disabled. Dry-run can also be chanied with
`--yes` and `--use-previous-options` for non-interactive modes.

Dry-run is like a normal run with changes replaced by diff.

Fixes #2530

Co-authored-by: Cian Johnston <cian@coder.com>

cli/configssh_test.go

@@ -494,6 +494,26 @@ func TestConfigSSH_FileWriteAndOptionsFlow(t *testing.T) {
 				"--yes",
 			},
 		},
+		{
+			name: "Do not overwrite config when using --dry-run",
+			writeConfig: writeConfig{
+				ssh: strings.Join([]string{
+					baseHeader,
+					"",
+				}, "\n"),
+			},
+			wantConfig: wantConfig{
+				ssh: strings.Join([]string{
+					baseHeader,
+					"",
+				}, "\n"),
+			},
+			args: []string{
+				"--ssh-option", "ForwardAgent=yes",
+				"--dry-run",
+				"--yes",
+			},
+		},
 
 		// Tests for deprecated split coder config.
 		{