New plugin demo

[rock3r]

A new, more complex plugin sample that shows the Swing and Compose implementations in parallel.

Notes:

• Bold fonts don't load for some reason in the Compose sample (see IDE plugin can't access font variants #162)
• Images in Swing are possibly not loaded/painted the right way, but I don't know a better way to do it
• Images in Swing are fill-width, whereas in Compose they are fitted to the available space. I'd like a splitter to resize them. Even better would be having a layout breakpoint to change the layout when there is enough room to have the image side-by-side with the text in Compose. I can't be bothered to do it in Swing, it's too much work
• The image in Compose has a shader applied to it on hover, because I can, but the shader is broken and needs fixing
• The splitter in Compose has a 1-px-wide drag area, which is obviously not great
• The Compose selected item is reset when leaving the tab, it should likely be stored in the service instead, but this is good enough for now
• The tags in the Compose version are clickable and set the filter — can't do that in Swing
• Tags' text colour is not correct in Swing (it probably gets overridden by virtue of being in a list item renderer) and I can't be bothered to make it work by fighting Swing.

Swing version

Compose version