Enhance/pdf improvements (#6475)

Full-text search, highlights and assets alias support 
It also exposes a plugin API for highlight context menu   
    ```ts
    /**
       * Current it's only available for pdf viewer
       * @param label - displayed name of command
       * @param action - callback for the clickable item
       * @param opts - clearSelection: clear highlight selection when callback invoked
       */
      registerHighlightContextMenuItem: (
        label: string,
        action: SimpleCommandCallback,
        opts?: {
          clearSelection: boolean
        }
      ) => unknown
    ```

src/main/frontend/utils.js

@@ -291,15 +291,6 @@ export const toPosixPath = (input) => {
   return input && input.replace(/\\+/g, '/')
 }
 
-// Delegation of Path.js but unified into POXIS style
-// https://nodejs.org/api/path.html#pathparsepath
-// path.parse('/home/user/dir/file.txt');
-// Returns:
-// { root: '/',
-//   dir: '/home/user/dir',
-//   base: 'file.txt',
-//   ext: '.txt',
-//   name: 'file' }
 export const nodePath = Object.assign({}, path, {
   basename (input) {
     input = toPosixPath(input)