Change color of testnet UI

[ebma]

Changes the color of primary and submit buttons when using a testnet account and testnet badges to a pink color. This way the user always has a more obvious indicator when doing things with a testnet account. Admittedly,
this is a rather eye-catching color but then again the goal is to make the user aware he is not using mainnet at the moment.

• Add a testnet prop to the <ActionButton> component
• Add colors for testnet to the theme
• Show the pink color for action buttons when the testnet prop is set and the button is of type primary or submit
• Allow same account name for accounts on different networks

Closes #1010.

[andywer]

@ebma One last thing: Let's make all testnet badges magenta then, incl. the one on the account view header 😉

[ebma]

Done. Looks like this:

By the way I noticed that the title of the trading dialog does not have a testnet badge next to it. Seems like a mistake since it's in most other relevant dialogs @andywer?

[andywer]

@ebma Yes, let's add the badge to the trading dialog, too 👍

[ebma]

I've added the testnet badge in a separate PR #1164.