* Fixes#3541
* CSV export now includes TOTP settings, Entry Icon (database icon number only), Modified Time, and Created Time.
* CSV import properly understands time in ISO 8601 format and Unix Timestamp.
* CSV import will set the TOTP settings and entry icon based on the chosen column.
* Changed `Extract` to `Export` to support additional formats
* Allow database expot as CSV. Added a `--format` option to the `Export` command for that, which defaults to xml, so the current behavior is unchanged.
*The `CsvExporter` had to be refactored a bit, but nothing major. It can
now print to a file or return a string.
The Database, DatabaseWidget, and DatabaseTabWidget classes share many responsibilities in inconsistent ways resulting in impenetrable and unmaintainable code and a diverse set of bugs and architecture restrictions. This patch reworks the architecture, responsibilities of, and dependencies between these classes.
The core changes are:
* Move loading and saving logic from widgets into the Database class
* Get rid of the DatabaseManagerStruct and move all the information contained in it into the Database
* Let database objects keep track of modifications and dirty/clean state instead of handing this to external widgets
* Move GUI interactions for loading and saving from the DatabaseTabWidget into the DatabaseWidget (resolves#2494 as a side-effect)
* Heavily clean up DatabaseTabWidget and degrade it to a slightly glorified QTabWidget
* Use QSharedPointers for all Database objects
* Remove the modifiedImmediate signal and replace it with a markAsModified() method
* Implement proper tabName() method instead of reading back titles from GUI widgets (resolves#1389 and its duplicates #2146#855)
* Fix unwanted AES-KDF downgrade if database uses Argon2 and has CustomData
* Improve code
This patch is also the first major step towards solving issues #476 and #2322.
This patch aims at reducing the number of copies for obejcts that could
be referenced rather than copied, because they're not modified during
the computation.
