(css) Drop unused "theme" Sass files

Only the original ng-material theme files are used in the build process
of ng-material (using gulp).

UI/WebServerResources/scss/components/input/input-theme.scss

@@ -1,50 +0,0 @@
-md-input-container.md-THEME_NAME-theme {
-  .md-input {
-    @include input-placeholder-color('{{foreground-3}}');
-    color: '{{foreground-1}}';
-    border-color: '{{foreground-4}}';
-    text-shadow: '{{foreground-shadow}}';
-  }
-
-  label {
-    text-shadow: '{{foreground-shadow}}';
-    color: '{{foreground-3}}';
-  }
-
-  &.md-input-focused {
-    .md-input {
-      border-color: '{{primary-500}}';
-    }
-    label {
-      color: '{{primary-500}}';
-    }
-    &.md-accent {
-      .md-input {
-        border-color: '{{accent-500}}';
-      }
-      label {
-        color: '{{accent-500}}';
-      }
-    }
-    &.md-warn {
-      .md-input {
-        border-color: '{{warn-500}}';
-      }
-      label {
-        color: '{{warn-500}}';
-      }
-    }
-  }
-
-  &.md-input-has-value:not(.md-input-focused) {
-    label {
-      color: '{{foreground-2}}';
-    }
-  }
-
-  .md-input[disabled] {
-    border-bottom-color: transparent;
-    color: '{{foreground-3}}';
-    background-image: linear-gradient(to right, '{{foreground-4}}' 0%, '{{foreground-4}}' 33%, transparent 0%);
-  }
-}