Toolbar tool tips have inconsistencies

[vandyliu]

This is most notable for the micro:bit simulator.

1. Some icons have two tooltips (one bigger and one smaller) and some only have one. We should probably just have one.
2. Sometimes when there are two tooltips, they have contradicting titles.
3. Temperature sensor and light sensor tooltips are typed like constant names instead of titles.
   
   

[xnkevinnguyen]

Closed with this PR #359