Telegram bot support /register command for admin

[0xk2]

This function make it easier for admin to register a chat channel. However, admin can do it through webapp so this is something for the future.

[0xk2]

/register will create a community if it is not yet created: /register [POINT_NAME] [DAYS_TO_EXPIRE]

• create/reuse a kp for the admin. Only admin of the group can /register
• it also create kp for each member of the community, reuse kp if it is already created for this telegram handle
• return error if the community is already registered

Note, use this for kp storage

const mnemonic = bip39.generateMnemonic(); // mnemonic is a `varchar`
const seed = bip39.mnemonicToSeedSync(mnemonic).slice(0, 32);
const keypair = Keypair.fromSeed(seed);