Refactoring: switch every explicit "= null" to using Optional

[awoo-civ]

We should never use nulls to represent something that may be empty. We should use Optionals instead.

[vipinpanwar]

Hey @awoo-civ
I dug into the codebase and found a few spots where we currently do this and could swap in Optional.empty():

Fields

SnitchFieldPreview snitchFieldToPreview = null;

Snitch lastBrokenSnitch = null;

SnitchesStore store = null;

Methods
getSnitch() method

If you’re ok with that scope, I can pick these areas, refactor it to use Optional, and update call-sites to use ifPresent().

[awoo-civ]

@vipinpanwar Hey, yes! That's exactly what I had in mind 😃

snitch.getType() also needs this treatment: 9695356

[vipinpanwar]

Hey @awoo-civ
I’ve made the requested updates—could you please review the PR and share any feedback? This is my first OS contribution.
https://github.com/Gjum/SnitchMod/pull/53/files