Add support for entry placeholders

[mateuszdrab]

Description I have some entries where the ota field starts like this otpauth://totp/xxx::{S:eMail}? - Keepassium displays the whole URL, no TOTP code

This is because I have a different username and store emails in a field called eMail.

KeePassOTP generates the otaurls in the format containing the reference and it works fine in KeePass and KeePassXC.

How to reproduce Steps to reproduce the behavior:

• add a keepass entry with username set to {S:eMail} and add the eMail field
• add an OTP config using KeePassOTP

Expected behavior OTP is displayed

Environment:

• Device: iPhone 12 Pro Max
• OS: iOS 16
• App Version: 1.36.116

[keepassium]

Thank you and sorry for the delay.

The reason is that, {S:} is a placeholder rather than a reference. Semantically they are very similar, but references start with {REF:. At the moment, KeePassium supports references but not placeholders.

I will requalify this as a feature request then, if you don't mind.