Use .text-overflow() mixin from 'mediawiki.mixins'

Removing MinervaNeue's own mixin now that it's possible.
Also unify code instances to use new mixin.

Depends-On: Ia8d6e7229b49598b0f4cb19dff463ffe2f11a43d
Change-Id: Iaffcefcb7a239d5ddecbe17097573d06099de88e

minerva.less/minerva.mixins.less

@@ -76,10 +76,3 @@
 	margin-top: 0.5em;
 	line-height: 1.4;
 }
-
-.truncated-text() {
-	white-space: nowrap;
-	overflow: hidden;
-	-webkit-text-overflow: ellipsis;
-	text-overflow: ellipsis;
-}

resources/skins.minerva.base.styles/footer.less

@@ -47,7 +47,7 @@ footer {
 		line-height: @line-height-content;
 		vertical-align: middle;
 		flex-grow: 1;
-		.truncated-text();
+		.text-overflow( @visible: false );
 	}
 
 	> .post-content {

resources/skins.minerva.mainMenu.styles/MainMenuItem.less

@@ -44,12 +44,10 @@
 			a {
 				color: @colorGray5;
 				display: block;
-				// Overflowing text is ellipsized.
 				max-width: 100%;
-				text-overflow: ellipsis;
-				white-space: nowrap;
-				overflow: hidden;
 				padding: @menuLinkLineHeight / 2 10px @menuLinkLineHeight / 2 15px;
+				// Overflow text is ellipsized in one line.
+				.text-overflow( @visible: false );
 
 				// T233166
 				&.secondary-action {

resources/skins.minerva.scripts/styles.less

@@ -46,7 +46,7 @@
 
 // Used by last modified and Main Menu items
 .truncated-text {
-	.truncated-text();
+	.text-overflow( @visible: false );
 }
 
 @-webkit-keyframes fadeInImage {

skinStyles/mediawiki.ui.icon/mediawiki.ui.icon.less

@@ -51,8 +51,6 @@
 	// reset font-size so the "em" value is relative to the more
 	// predictable rem font size ...and no rems because we can't have nice things.
 	font-size: initial;
-	white-space: nowrap;
-	text-overflow: ellipsis;
 
 	// sizing
 	position: relative;
@@ -71,7 +69,9 @@
 	// alignment
 	vertical-align: middle;
 	line-height: 0;
-	overflow: hidden;
+
+	// Overflow ellipsis.
+	.text-overflow( @visible: false );
 
 	// resetting styles for <button> elements
 	-moz-appearance: none;

skinStyles/mobile.special.styles/minerva.less

@@ -48,7 +48,7 @@
 
 // Used by MobileSpecialPageFeed.php in MobileFrontend
 .truncated-text {
-	.truncated-text();
+	.text-overflow( @visible: false );
 
 	// FIXME: this works only in WebKit
 	&.multi-line {