[ftr] Replace the LinkController with a more powerful ComponentController

[DennisFriedl]

The Problem
With the functionality of the Edirom getting more and more replaced with Web Components, a controller solution based on a plist is not making full use of the many different ways Web Components can be manipulated.

What is Wanted
I want the Edirom to for example:

• open the Concordance Navigator Component with a specific condordance, a specific group and a specific measure already selected.
• open the Videoplayer Component at a specific measure in a video, with the german audio track selected, the replay speed set at 0.5 and a loop between the seconds 6 and 12.

This would make the Controller way more powerful and flexible. I could use this with my WebSocket Component to control the Edirom from outside in a very detailed way by manipulating each Web Component as I like.
One could also imagine that this rework would make it possible to snapshot the "state" of an open Edirom and work with exactly that state at a later date or send this state to someone else.

The rework would e.g. affect this issue: #382

A Solution
Web Components can be manipulated by changing the attributes and values of the HTML element of the Component. A ComponentController would handle a JSON object with:

• A list of Web Components to be opened or manipulated
• A list of attributes and values per Component to be changed. A path to a MEI file or image to be opened in the Faksimile Viewer Component would also be just an attribute + value for example.
• Other "meta" configurations per Component, e.g. "useExisting", "onlyExisting" etc.

[daniel-jettka]

Thanks @DennisFriedl for the good description. Sounds very good.

Just for me and maybe others... This is the current LinkController.js: https://github.com/Edirom/Edirom-Online/blob/develop/app/controller/LinkController.js