ui: merge prompt text components into a singe string
This will help avoid problems with partial or mismatched translation
of the components.
i18n-ru: update po-file for further translation (from
ddc7a6be2021)
i18n-ru: fix patchbomb confirmation prompt (
issue3929)
Recognize y(es) and (n)o as valid input, for user not to have to switch
keyboard layout twice (`hg email -o ...` is Latin, whereas д(а)/н(ет) are not).
Use capital Y/N letters in prompt, otherwise y could be mistaken for у, and n
- for п.