Add tooltip to the "more languages" action to provide better context

Bug: T135224
Change-Id: I3c5d909ff334182e25b48fd3917260087ee276ef

extension.json

@@ -246,7 +246,8 @@
 				"mediawiki.ui.button"
 			],
 			"messages": [
-				"ext-uls-compact-link-count"
+				"ext-uls-compact-link-count",
+				"ext-uls-compact-link-info"
 			],
 			"localBasePath": "resources",
 			"remoteExtPath": "UniversalLanguageSelector/resources"

i18n/en.json

@@ -61,6 +61,7 @@
 	"ext-uls-input-disable-notification-info-interlanguage": "You can enable the input tools at any time from the language settings next to the language list.",
 	"ext-uls-language-settings-applying": "Applying...",
 	"ext-uls-compact-link-count": "{{PLURAL:$1|One more|$1 more}}",
+	"ext-uls-compact-link-info": "All languages (initial selection from common choices by you and others)",
 	"apihelp-languagesearch-description": "Search for language names in any script.",
 	"apihelp-languagesearch-param-search": "Search string.",
 	"apihelp-languagesearch-param-typos": "Number of spelling mistakes allowed in the search string.",

i18n/qqq.json

@@ -63,6 +63,7 @@
 	"ext-uls-input-disable-notification-info-interlanguage": "Notification bubble text when input methods are disabled, appears if the ULS is at interlanguage toolbar",
 	"ext-uls-language-settings-applying": "Label for apply settings button in language settings screen, while settings being saved. Please keep it short.",
 	"ext-uls-compact-link-count": "Message next to list of languages which indicates that there are more languages than the ones shown. Parameters:\n* $1 - number of languages\n{{Identical|More}}",
+	"ext-uls-compact-link-info": "Tooltip for a button that shows all available languages next to short list of relevant languages",
 	"apihelp-languagesearch-description": "{{doc-apihelp-description|languagesearch}}",
 	"apihelp-languagesearch-param-search": "{{doc-apihelp-param|languagesearch|search}}\n{{Identical|Search string}}",
 	"apihelp-languagesearch-param-typos": "{{doc-apihelp-param|languagesearch|typos}}",

resources/js/ext.uls.compactlinks.js

@@ -352,6 +352,7 @@
 
 			$trigger = $( '<button>' )
 				.addClass( 'mw-interlanguage-selector mw-ui-button' )
+				.prop( 'title', mw.msg( 'ext-uls-compact-link-info' ) )
 				.text( mw.msg(
 					'ext-uls-compact-link-count',
 					mw.language.convertNumber( this.listSize - this.compactSize )