[Xwt.Gtk] Propagate LinkLabel click events through to the MarkdownView
[Xwt.Gtk] Propagate LinkLabel click events through to the MarkdownView

We now propagate the events from internal hyperlinks to the MarkdownView
so we can consistently handle them across the various toolkits.

mminns/xwt,hamekoz/xwt,iainx/xwt,hwthomas/xwt,lytico/xwt,TheBrainTech/xwt,residuum/xwt,directhex/xwt,mono/xwt,akrisiun/xwt,sevoku/xwt,mminns/xwt,cra0zy/xwt,steffenWi/xwt,antmicro/xwt