urls: add key binding that toggles whether URLs are displayed on jump-label

By default, the URL isn’t shown on the jump-label. For auto-detect
URLs, doing so is virtually always useless, as the URL is already
visible in the grid.

For OSC-8 URLs however, the URL is often _not_ visible in the
grid. Many times, seeing the URL is still not needed (if you’re doing
‘ls --hyperlink’, you already know what the URIs are).

But it is still useful to have a way to show the URLs.

This patch adds a new key binding action that can be used in url-mode
to toggle the URL on and off in the jump label.

It is bound to ctrl+t by default.

render.c

@@ -2525,6 +2525,8 @@ render_urls(struct terminal *term)
            + term->grid->num_rows) & (term->grid->num_rows - 1);
     const int view_end = view_start + term->rows - 1;
 
+    const bool show_url = term->urls_show_uri_on_jump_label;
+
     tll_foreach(win->urls, it) {
         const struct url *url = it->item.url;
         const wchar_t *key = url->key;
@@ -2562,13 +2564,28 @@ render_urls(struct terminal *term)
             continue;
         }
 
-        size_t chars = wcslen(key);
+        const size_t key_len = wcslen(key);
+
+        size_t url_len = mbstowcs(NULL, url->url, 0);
+        if (url_len == (size_t)-1)
+            url_len = 0;
+
+        wchar_t url_wchars[url_len + 1];
+        mbstowcs(url_wchars, url->url, url_len + 1);
+
+        size_t chars = key_len + (show_url ? (2 + url_len) : 0);
 
         const size_t max_chars = 50;
         chars = min(chars, max_chars);
 
         wchar_t label[chars + 2];
-        wcscpy(label, key);
+        label[chars] = L'…';
+        label[chars + 1] = L'\0';
+
+        if (show_url)
+            swprintf(label, chars + 1, L"%ls: %ls", key, url_wchars);
+        else
+            wcsncpy(label, key, chars + 1);
 
         for (size_t i = 0; i < wcslen(key); i++)
             label[i] = towupper(label[i]);