Fixing #94 and #106

[arteymix]

That's a bit of an odd watcher. Can you check if the clear all selection button at the bottom of the settings still work?

[oganm]

Nope very much broken..

Another new if not functionally too important issue is that if i

• select a mouse and a human microarray
• select human

the mouse microarray will still be selected despite not being part of the tree anymore

[oganm]

This latest commit fixes the clear all issue using a ref. I am unsure if keeping non-existent parts of the tree selected is a real issue since people may want to preserve their selections regardless

[oganm]

@arteymix this removes the components/PlatformSelector.js. it seemed to be an earlier version of TechnologyTypeSelector. and creates a platformConstants.js to import some constants. should be ready to be merged otherwise