Add Ability to Re-Calibrate Balance in Manual Accounts

This would be analogous to the ability to force a download in connected accounts. It is needed when the balance in a manual account is incorrect because of either counting a transaction twice or not counting one at all.

This problem has reoccured periodically for several years.

It would give the user the same level of control in a manual account he now has in connected accounts.

@RobWilk pointed out that the other idea that has been around for a while is different. It would allow the user to input any balance he would like without adding transactions or an adjustment. This idea allows the user to fix immediately Simplifi's computational errors.