Update useScaffoldEventHistory hook

[rin-st]

Description

1. Moved readEvents to useCallback, so it's clear which dependencies it has
2. Since fromBlock is required prop, removed if's like if (fromBlock)
3. Combined two useEffects with the same functionality readEvents(); and

   if (!deployedContractLoading) {
   readEvents();
   }

   The one without if (!deployedContractLoading) was buggy - on load it threw errors to the console

4. Changed default state of events to [], so we don't guess is it array or undefined

Additional Information

• [x] I have read the contributing docs (if this is your first contribution)
• [x] This is not a duplicate of any existing pull request

[rin-st]

Thanks! Merging this