Fix markdown math brackets render problem (#31420)

Close #31371, support `($ ... $)` like GitHub

Co-authored-by: wxiaoguang <wxiaoguang@gmail.com>
(cherry picked from commit 90a3c20e7996e2db577a51d37f2190e2e990a22a)

Conflicts:
	modules/markup/markdown/markdown_test.go
	trivial context conflict

modules/markup/markdown/markdown_test.go

@@ -548,6 +548,10 @@ func TestMathBlock(t *testing.T) {
 			`$$a`,
 			`<p>$$a</p>` + nl,
 		},
+		{
+			"$a$ ($b$) [$c$] {$d$}",
+			`<p><code class="language-math is-loading">a</code> (<code class="language-math is-loading">b</code>) [$c$] {$d$}</p>` + nl,
+		},
 	}
 
 	for _, test := range testcases {