Support . as a row:column separator in terminal link detector

The motivation here is the Sail language compiler which outputs errors conforming to the GNU style

https://www.gnu.org/prep/standards/html_node/Errors.html

I think they must be the only people in the world actually using the `line0.col0-line1.col1` format. I did have an attempt to capture the ending line/column but it is very difficult with regex, and not that useful anyway so I've opted for the simpler option of just ignoring the `-` part.

src/vs/workbench/contrib/terminalContrib/links/browser/terminalLinkParsing.ts

@@ -71,11 +71,14 @@ function generateLinkSuffixRegex(eolOnly: boolean) {
 	const lineAndColumnRegexClauses = [
 		// foo:339
 		// foo:339:12
+		// foo:339.12
 		// foo 339
 		// foo 339:12                             [#140780]
+		// foo 339.12
 		// "foo",339
 		// "foo",339:12
-		`(?::| |['"],)${r()}(:${c()})?` + eolSuffix,
+		// "foo",339.12
+		`(?::| |['"],)${r()}([:.]${c()})?` + eolSuffix,
 		// The quotes below are optional          [#171652]
 		// "foo", line 339                        [#40468]
 		// "foo", line 339, col 12