move copy_to_clipboard to behaviors directory as it is needed on all pages

[ci-skip]

app/assets/javascripts/behaviors/copy_to_clipboard.js

@@ -35,7 +35,7 @@ function genericError(e) {
   showTooltip(e.trigger, `Press ${key}-C to copy`);
 }
 
-$(() => {
+export default function initCopyToClipboard() {
   const clipboard = new Clipboard('[data-clipboard-target], [data-clipboard-text]');
   clipboard.on('success', genericSuccess);
   clipboard.on('error', genericError);
@@ -70,4 +70,4 @@ $(() => {
     clipboardData.setData('text/plain', json.text);
     clipboardData.setData('text/x-gfm', json.gfm);
   });
-});
+}

app/assets/javascripts/behaviors/index.js

@@ -1,6 +1,7 @@
 import './autosize';
 import './bind_in_out';
 import initCopyAsGFM from './copy_as_gfm';
+import initCopyToClipboard from './copy_to_clipboard';
 import './details_behavior';
 import installGlEmojiElement from './gl_emoji';
 import './quick_submit';
@@ -9,3 +10,4 @@ import './toggler_behavior';
 
 installGlEmojiElement();
 initCopyAsGFM();
+initCopyToClipboard();

app/assets/javascripts/main.js

@@ -44,7 +44,6 @@ import './commits';
 import './compare';
 import './compare_autocomplete';
 import './confirm_danger_modal';
-import './copy_to_clipboard';
 import Flash, { removeFlashClickListener } from './flash';
 import './gl_dropdown';
 import './gl_field_error';