Claiming worker rewards does not work as expected

[villesundell]

Describe the bug
Currently anyone can help anyone by claiming their worker rewards. This is a good feature, and is a good smart contract design convention (do not place unneeded restrains).

However, if the account is a new one, claiming would not be successful, since it tries to use claimant's RAM, which is not available if the action caller is not claimant.

Expected behavior
Either:

1. Only claimant can claim their rewards
   Or:
2. Error should be raised
   Or:
3. RAM ownership should be re-thought

Additional context
Problematic line is this:

telos-decide/contracts/decide/src/worker.cpp

Line 152 in b17261e

accounts.emplace(claimant, [&](auto& col) {

[DouglasHorn]

Of these options, #2, Raising an error message for not enough RAM is probably the easiest and a sufficient fix. There are times when an account would want to claim for another.