Add a "PSBT Operations" dialog, reached from the "Load PSBT..." menu
item, giving options to sign or broadcast the loaded PSBT as
appropriate, as well as copying the result to the clipboard or saving
it to a file.
- Update transifex slug
- Mention update of MSVC build in `doc/translation_process.md`
- Do a `make translate` to update English translations
- Pull current translations from transifex