[Data Source] Create Stake / Delegate CTA + Stake modal

[FrancoAguzzi]

Stake CTA + modal

• The stake CTA should display "Stake" label if user is a keyper
• The stake CTA should display "Delegate" label if user is a keyper
• The stake modal should display a Select Keyper Dropdown, a Number Input Slider, a table with Lock Period information, Expected Rewards and Average stkSHU - SHU conversion rate and a table with the step-by-step information on how to stake / delegate some amount of SHU
• The click of stake modal main CTA should trigger, at first, an amount approval request to user's wallet, and, if first transaction ran successfully, the Staking / Delegate SC call to do the stake
• If transaction fails, a toast message should be shown
• If transaction succeeds, a toast message should be shown
• By the end of the transaction, a "Refresh page" toast message should be displayed