[FEATURES] Custom CSV Export

[Aarekaz]

Please confirm the following

• [X] I checked the current issues for duplicate problems

What do you want to be added or improved?

As a user, I want to be able to import CSV transaction data exports from my banks/wallets or any other app that is not supported.

Why do you need it?

• Helps to import transactions even if the app is not supported
• Dev will also have to focus less on adding more app integrations if there is a specific standard to import.

How do you imagine it?

• A set of guidelines that explains the format in which the CSV must be. ( I can help in writing the documentation and guidelines for the format)
• A option in the import section of the app which lets a user select a CSV file from their storage.
• A quick view of the data to be imported so that the user can verify it's correct.