Add support for Contracts and Tokens

[husainfazel]

This is the current display in Expedition when you try to view a contract:

From a contract developer's point of view it would be useful to see

• If this is an ERC20 token, the name and symbol of the token
• Who created this contract

• Contract Transactions, Blockscout has a very useful log functionality which shows data/params in each transaction

• Also would be useful to see what tokens an account holds.

Not essential but nice to have

• Rich list, to see the top X accounts with a token balance
• Ability to make calls to a contract from the UI as well

Bugs / UI fixes
The contract byte code doesn't wrap properly