This change fixes input validation for the following cases:
- Check that entered account names are still available
- Working validation for time steps (input mask was completely broken)
- Allow longer tokens: liboath is no longer used, Keysmith can handle it
Additionally the QML code is refactored significantly:
- Extracted the main accounts overview page
- Extracted the add an account page
- Completed the internal renaming of "Oath" to "Keysmith" for QML types
This change is a workaround for behaviour of QML controls: when fixup is
called during input validation, the `acceptableInput` property is not
updated correctly.
- Add a new static library "validator_lib" covering the "validators" namespace in C++
- Introduce the Base32Validator to perform input field validation with fixup support