implement per-wallet lock quota and rate limit

[HayimShaul]

implement per-wallet lock quota and rate limit.
Addresses issue #1640

[adecaro]

if I understand correctly the concerns of the issue this PR is trying to address, the selector service needs to have a definition of a Locker whose lock function takes in input also the wallet id the tokens are selected for. Then, we need to enforce that both simple and sherdlock selectors use this function. At that point the job of the token-sdk is done. We can update the documentation and tell the developer how to provide a new implementation of the Locker interface that integrate rate limiting. The application that uses the token-sdk can already have an overall infrastructure for rate limiting (using redis, for example) and they might want to reuse it as well.

[HayimShaul]

if I understand correctly the concerns of the issue this PR is trying to address, the selector service needs to have a definition of a Locker whose lock function takes in input also the wallet id the tokens are selected for. Then, we need to enforce that both simple and sherdlock selectors use this function. At that point the job of the token-sdk is done. We can update the documentation and tell the developer how to provide a new implementation of the Locker interface that integrate rate limiting. The application that uses the token-sdk can already have an overall infrastructure for rate limiting (using redis, for example) and they might want to reuse it as well.

I'm not sure I understand. Are you suggesting the rate limit be implemented by the application calling tokensdk?
Then why do we need a new Locker?