chore: Minor code improvements

- Changed variable name in `get_content` function
- Added proper exceptions for `get_topic` and `get_content` functions in lms

erpnext/public/js/education/lms/components/Video.vue

@@ -55,7 +55,7 @@ export default {
     methods: {
         getContent() {
             return lms.call('get_content', {
-                type: this.type,
+                content_type: this.type,
                 content: this.content
             })
         }