feat(key): add 'ipfs key ls' as alias for 'ipfs key list'

[VedantMadane]

Summary

Fixes #10976 - Add ipfs key ls as an alias for ipfs key list.

Problem

The CLI is inconsistent with list vs ls. Commands like ipfs repo and ipfs pin use ls instead of list, but ipfs key only supports list.

Solution

Add ls as an alias for the list subcommand in ipfs key to be consistent with other ipfs commands.

Changes

• Added "ls": keyListCmd to the subcommands map in core/commands/keystore.go

Testing

# Before (would fail)
$ ipfs key ls
Error: unknown subcommand "ls"

# After (works the same as 'list')
$ ipfs key ls
self
mykey