Switch to IsarDb from SQLite

[mijiga]

Justification

Unless there was a particular reason for using SQLite, let's migrate to IsarDb because:

• It abstracts a lot of the technicalities to do with the creation and management of the DB and tables themselves
• It uses the concept of collections which is perfect for this use case - a simple app
• 1 & 2 make it beginner friendly
• It has full-text search and a filters built in
• It's arguably the standard which makes it easier to work with it's also not too far from Android's RoomDB which is also a standard hence soft landing for Android devs

[zikani03]

@mijiga Great suggestion, especially sounds useful if we can find a smooth way to deal with migrations and search. Do you want to work on a PR for this?

[mijiga]

@mijiga Great suggestion, especially sounds useful if we can find a smooth way to deal with migrations and search. Do you want to work on a PR for this?

@zikani03 yeah. I actually just finished one. #43