jose fmt: Please implement shotcuts for operations on deep hashes.

[cbiedl]

Hello,
fetching a value from a nested hash requires a lot of --get:

echo '{"level1":{"level2":{"level3":{"key":"value"}}}}' | \
    jose fmt --json=- --object  --get level1 --get level2 --get level3 --get key --unquote=-

It was nice if the keys could be concatenated so this can be written in a shorter form like:

echo '{"level1":{"level2":{"level3":{"key":"value"}}}}' | \
    jose fmt --json=- --object  --get level1.level2.level3.key --unquote=-

Bonus: Make the separator (currently: dot) configurable.

Related, it was nice if -U/--unwind could understand an optional repetition value, so (taken from clevis-encrypt-tang):

jwe="$(jose fmt -j "$jwe" -g protected -g clevis -g tang -q "$url" -s url -UUUUo-)"

could be written as

jwe="$(jose fmt -j "$jwe" -g protected -g clevis -g tang -q "$url" -s url -U4 -o-)"

PS: To make sure: This is not at all about short/long parameter names.