Bugfix/cbw 1059 crash on amount input

[orhoj]

Purpose

Fix an issue in the baking and delegation where setting a too large amount (greater than what can be stored in a Long) caused a crash.

Please note that this is just a quickfix. In the future the input field should be updated so that it prevents the user to input invalid values like how it is in the iOS app.

Changes

• Correctly return an error when amount is not a Long.

Checklist

• [x] My code follows the style of this project.
• [x] The code compiles without warnings.
• [x] I have performed a self-review of the changes.
• [x] I have documented my code, in particular the intent of the hard-to-understand areas.
• [x] (If necessary) I have updated the CHANGELOG.

[github-actions[bot]]

File	Coverage [19.54%]	:x:
StakeAmountInputValidator.kt	19.54%	:x:

Total Project Coverage	0.91%	:x: