MDL-59843 mod_choice: Fix horizontal display mode

This re-implements the feature in the boost and bootstrap themes.

theme/boost/scss/moodle/modules.scss

@@ -9,6 +9,14 @@ select {
     width: auto;
 }
 
+// Choice module
+
+.path-mod-choice {
+    .horizontal .choices .option {
+        display: inline-block;
+    }
+}
+
 .path-mod-feedback .feedback_form .col-form-label {
     display: block !important; /* stylelint-disable-line declaration-no-important */
 }

theme/bootstrapbase/less/moodle/modules.less

@@ -266,6 +266,10 @@ div#dock {
         float: left;
         padding-right: 1em;
     }
+
+    .horizontal .choices .option {
+        display: inline-block;
+    }
 }
 
 // Lesson module