Add translations for ne wsort widget in "My rules"

Related issue:
- https://github.com/uBlockOrigin/uBlock-issues/issues/1055

src/_locales/en/messages.json

@@ -551,6 +551,22 @@
     "message": "Rule syntax: <code>source destination type action</code> (<a href='https://github.com/gorhill/uBlock/wiki/Dynamic-filtering:-rule-syntax'>full documentation</a>).",
     "description": "English: dynamic rule syntax and full documentation."
   },
+  "rulesSort": {
+    "message": "Sort:",
+    "description": "English: label for sort option."
+  },
+  "rulesSortByType": {
+    "message": "Rule type",
+    "description": "English: a sort option for list of rules."
+  },
+  "rulesSortBySource": {
+    "message": "Source",
+    "description": "English: a sort option for list of rules."
+  },
+  "rulesSortByDestination": {
+    "message": "Destination",
+    "description": "English: a sort option for list of rules."
+  },
   "whitelistPrompt": {
     "message": "The trusted site directives dictate on which web pages uBlock Origin should be disabled. One entry per line. Invalid directives will be silently ignored and commented out.",
     "description": "The name of the trusted sites pane."

src/dyna-rules.html

@@ -35,7 +35,7 @@
                 <button type="button" class="iconifiable important disabled" id="editSaveButton"><span class="fa">&#xf0c7;</span><span data-i18n="rulesEditSave"></span></button>
             </div>
             <div id="ruleFilter">
-                <span><span class="fa-icon">filter</span>&nbsp;<input type="search" size="20"></span>&emsp;Sort:&nbsp;<select><option value="0" selected>Rule type<option value="1">Source<option value="2">Destination</select>&emsp;<span id="diffCollapse" class="fa-icon">double-angle-up</span>
+                <span><span class="fa-icon">filter</span>&nbsp;<input type="search" size="16"></span>&emsp;<span data-i18n="rulesSort"></span>&nbsp;<select><option value="0" selected data-i18n="rulesSortByType"><option value="1" data-i18n="rulesSortBySource"><option value="2" data-i18n="rulesSortByDestination"></select>&emsp;<span id="diffCollapse" class="fa-icon">double-angle-up</span>
             </div>
         </div>
     </div>