Consider updating xterm.js (3.3.0) to support multi-line links in terminal

[AlexTugarev]

Milestone 3.3.0 is almost complete, see https://github.com/xtermjs/xterm.js/milestone/24?closed=1.

Especially the multi-line link matching is worth looking into an upgrade once it's released.

BTW the vscode-xterm package is basically the master state of xterm.

[svenefftinge]

@AlexTugarev you mentioned that you have tested the vscode version and that it worked nicely.
If that is the case and it is more regularly updated we should use it, too.

[AlexTugarev]

As we depend on ^3.0., we've updated it automatically with recent yarn.lock update.