Description

This PR adds the option to set a "topic" (basically any string you provide) for every scan you make and puts that string into the filename.
If you enable the option in the settings there will be dialog after every scan asking to set a topic.

The idea is that i want to scan invoices/receipts and have all those scans searchable by filename. So if i have a receipt from book store "books haven" i'd scan that receipt and put "books haven" as topic. If i ever need to find that receipt i can just search all the scan files for the book store name.

This is the most basic and (hopefully) least invasive approach i could think off.
As a next increment i could imagine additionally having a predefined (but customizable by the user) list of document types like invoice, receipt, ticket, you name to enable users to add somewhat of a system to their scans

Fixes

it does not fix the issue #183 but tackles the first requirement (Allow assigning a name to each document directly after scanning.)

Type of change

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to not work as expected)

How Has This Been Tested?

Please describe the tests that you ran to verify your changes.

• ./gradlew assembleDebug assembleRelease
• ./gradlew checkstyle

Checklist:

• My code follows the style guidelines of this project
• I have performed a self-review of my own code
• I have commented my code, particularly in hard-to-understand areas
• I have made corresponding changes to the documentation
• My changes generate no new warnings