InstaBudget

- Fetch transactions from Plaid
- Insert into transaction table if necessary (check if Plaid transaction ID is already there, check if we can find a manually entered transaction that matches closely)
- Keep transaction entered this way as 'pending review'

- Show PlaidLink when needed and retrieve the access_token once the user has entered their information into Plaid.
- Store access_token and other relevant information needed when linking.

Instead of recomputing the running_balance all the time store it in the database. This is step one before being able to load transactions by page instead of all at once.

I added the service worker and the manifest required to make InstaBudget installable.