Adds airdropAddress to the request to join params and a is_airdrop_address flag in the communities_requests_to_join_revealed_addresses table.
This airdropAddress is used by the owner to know which address to use when airdropping
Improve `RequestToJoinCommunity` to accept `Addresses` in the request. If `Addresses` is not empty, we then only pass to the owner the selected addresses. The others are ignored.
Does not validate that the addresses in the slice are part of the user's wallet. Those not part of the wallet are just ignored.
This commit extends the `CommunityRequestToJoin` with `RevealedAddresses` which represent wallet addresses and signatures provided by the sender, to proof a community owner ownership of those wallet addresses.
**Note: This only works with keystore files maanged by status-go**
At high level, the follwing happens:
1. User instructs Status to send a request to join to a community. By adding a password hash to the instruction, Status will try to unlock the users keystore and verify each wallet account.
2. For every verified wallet account, a signature is created for the following payload, using each wallet's private key
``` keccak256(chatkey + communityID + requestToJoinID) ``` A map of walletAddress->signature is then attached to the community request to join, which will be sent to the community owner
3. The owner node receives the request, and if the community requires users to hold tokens to become a member, it will check and verify whether the given wallet addresses are indeed owned by the sender. If any signature provided by the request cannot be recovered, the request is immediately declined by the owner.
4. The verified addresses are then added to the owner node's database such that, once the request should be accepted, the addresses can be used to check on chain whether they own the necessary funds to fulfill the community's permissions
The checking of required funds is **not** part of this commit. It will be added in a follow-up commit.
Jonathan Rainville
Pascal Precht
Andrea Maria Piana