Add expiration preset "Same as last time"

[notevenaperson]

Summary

After renewing a password it is common to want to set the same expiration duration as last time.

Examples

A menu item under the Presets menu like this:
Repeat (5 months)
(In the case the last expiration duration was 5 months)

Context

Currently I have to write down the usual duration in the Notes for the entry so I can remember to set it again when it expires.
This button could also save time for setting non-preset durations, since you currently can't customize presets (#6800)

[droidmonkey]

See #6456, this will be implemented for 2.8.0