Gasless staking

[Ivshti]

Implement a feature where users can simply send ADX to an address (no matter where from) and it will be staked via the AdEx Relayer, if it's over a given threshold, upon calling a route (newly implemented) on it

If under the threshold, the user may stil stake it through the UI

Using this feature, you will be able to stake directly from Binance

Originally this feature was planned to be automatic but later on we decided to have it be triggered manually with a button, cause:

• enables users to 'gather' ADX from multiple places to reach the threshold
• enables users to send test transactions to ensure things are working - reflect this in the UI (@alesinka)
• enables doing this more than once, as well as if the identity is already deployed - as we can prompt the user to sign the transactions authorizing addBond
• easier implementation in the relayer

We must also explain to the user by "explain this address" note: explain it's an autogenerated smart contract

Relayer route

The relayer route must:

• use the staking code to calculate the identity addr on demand to ensure that it's the correct one
• measure the total ADX staked/owned by this account - allow transactions only if it's over the threshold amount
• allow transactions only if there isn't one in the last N hours

Otherwise it will be a pretty generic deploy-or-execute type of thing, same as /identity/execute

[alesinka]

Here is an initial mockup of the Gasless page (we could think of a cool creative header image instead of the three icons), comments are welcome: