Set expires field with a relative time duration

### Checks

- [x] I have read the Wiki, searched the open issues, and still think this is a new feature.

### Explain the problem clearly and succinctly:

### Problem
The _Expires_ field can only be set with a date and not with a relative time duration (expires in 90 days, 1 month, etc.)

### Describe the solution you'd like:

### Solution
The _Expires_ field could have a relative time duration input to calculate the expiration date automatically from today (or maybe even from an other date).
### Example
I want an entry to expire in 90 days, but with the current implementation I have to derive the expiration date manually.

### Describe alternatives you've considered:

_No response_

### Additional context:

### Similar implementations
A similar implementation for this issue is present it KeePassXC where you can choose a preset (1 month, 1 year, etc.) alongside the date picker.

Start by locating the Expires field and its existing date-picker entry point in the Android application, then review how expiration dates are stored and displayed. Compare the requested behavior with the KeePassXC implementation mentioned in the issue; done means users can enter a relative duration such as 90 days or a preset and obtain the corresponding expiration date.

Written by the indexing model from the issue text.