Loading status indicator / 'readiness' indicator for `useContract`

Contracts take some time to load. Right now, if someone wrote this:

const greeterContract = useContract(xxx,xxx);

Then greeterContract will go through the following lifecycle:

null          ---->           { } (empty object)        ---->            actual contract object (ready)

Because of that weird empty object state in the middle, just doing

if (!greeterContract)

doesn’t work.

We need to ship an indicator that notifies the user when the contract is ready. Something like:

const [contract, ready] = useContract(___, ___);

// ready becomes true when the contract has finished loading

[catalin-casuneanu]

@Dhaiwat10 Hello! I was blocked for a second by the thought that this is too easy 😅 Anyhow, I made a PR, please review it when you have the time and if there are any improvements that I can make, please let me know. Also, do I need a Changeset?

[Dhaiwat10]

Actually, I think we need a minor bump lol. Sorry for the confusion @CatalinCsnMaster