Unsubscribe action for donors and sponsors

[xavier506]

Dep: #734

As a donor or sponsor I should be able to unsubscribe from my user profile so that I can opt-out of the app

ACTION lifebankcode::unsubscribe(name user, eosio::asset community_asset)
{
  require_auth(user);
  check_consent(user);

• [x] Check with @xavier506 why lifebanks not included in this issue.
• [x] Check smart contract. @leisterfrancisco
• [x] Check if the feature is available (it is in smart contracts)
• [x] Design and front-end for the user interface

[murillojorge]

Close account seems more understandable to me from the user perspective. Check it out: https://zpl.io/awo56GK

[murillojorge]

The users will need a warning dialog: https://zpl.io/2jnqYyr

[leisterfrancisco]

Solved by https://github.com/eoscostarica/lifebank/pull/817