Implement simple placeholder icons for all entry kinds supported in the Suggestion Database. The icons are planned to be used in Component Browser as default icons for entries. This is intended to allow visually distinguishing different entry kinds.
The following additional fixes and tweaks are applied:
- Icons previously using only 1 color from the theme now use the color provided through shape parameters instead.
- The `data_science` and `network` icons now use only the 2 colors provided through shape parameters.
- The `join` icon has its shape and colors modified and uses only the 2 colors provided through shape parameters.
- The demo scene now parametrizes icon shapes using colors from the Component Browser Design Doc.
https://www.pivotaltracker.com/story/show/182584322
#### Visuals
Original contents of the demo scene before the PR:
<img width="2197" alt="x-orig" src="https://user-images.githubusercontent.com/273837/176669422-ee2e14c7-9ef4-42fd-acb7-ae3be6b68587.png">
Final contents of the demo scene after the PR:
<img width="2201" alt="x2-final" src="https://user-images.githubusercontent.com/273837/176668720-6f1685fd-f7e6-44d7-85f5-f6a6d6789644.png">
This PR extends the Component Group Entry with icon and option to highlight the text. Here the convert has highlighted "con".
https://user-images.githubusercontent.com/3919101/169046537-4f8b823c-322e-40dc-8abb-24d1d7092341.mp4
### Important Notes
Although this PR includes effort for adjusting Component Group style to better reflect the design, it is not entirely finished: the selection still works badly and will be fixed in another PR.
