Generate default name when using account import

[franciszekjob]

Which component is your feature related to?

Cast

Feature Request

When using account import we should be able to use it without passing name which is currently required. Cast should use default (available) or automatically generated name.

Current usage

sncast account import \
    --name abc111 \
    --address 0x1bbc22958cbc7a37bf8d787fc693ec296c0f46834fe6027054e3fb47d3edf75 \
    --private-key 0x1 \
    --type oz  \
    --url http://127.0.0.1:5050/rpc

Usage after implementation

sncast account import \
    --address 0x1bbc22958cbc7a37bf8d787fc693ec296c0f46834fe6027054e3fb47d3edf75 \
    --private-key 0x1 \
    --type oz  \
    --url http://127.0.0.1:5050/rpc

Both command such succeed with such output:

command: account import
add_profile: --add-profile flag was not set. No profile added to snfoundry.toml