Set default style to link-button mixin (#7340)

It was identified that we currently have 3 different behaviors for links used in the application. In issue #1778, it was discussed a set of good practices that we should follow in order to obtain consistency between links.

Currently, the link-button mixin is already used by the 'Clear all' button in the Active Filters block, so the idea was to increment it with a common pattern (font size small, font-weight normal, underlined by default and not underlined when on hover) that can be reused by other components (for example FilterResetButton).

* Change link-button mixin to make it attend the expected default style for links

* Replace text-button with link-button mixin in FilterResetButton component

assets/css/abstracts/_mixins.scss

@@ -163,7 +163,15 @@ $fontSizes: (
 // Reset <button> style so we can use link style for action buttons.
 @mixin link-button() {
 	@include text-button();
+	@include font-size(small);
 	text-decoration: underline;
+	font-weight: normal;
+	color: inherit;
+
+	&:hover {
+		text-decoration: none;
+		color: inherit;
+	}
 }
 
 // Makes sure long words are broken if they overflow the container.

assets/js/base/components/filter-reset-button/style.scss

@@ -1,11 +1,7 @@
 .wc-block-components-filter-reset-button {
-	@include text-button();
+	@include link-button();
 	cursor: pointer;
 
-	&:not([disabled]):hover {
-		text-decoration: underline;
-	}
-
 	&[disabled] {
 		cursor: not-allowed;
 	}

assets/js/blocks/active-filters/style.scss

@@ -20,11 +20,10 @@
 	overflow: hidden;
 
 	.wc-block-active-filters__clear-all {
-		@include font-size(small);
+		@include link-button();
 		border: none;
 		margin-top: 15px;
 		padding: 0;
-		text-decoration: underline;
 		cursor: pointer;
 		float: right;