Feature Request: Generate random passwords with CLI via dedicated command (e.g. `op generate`)

Ah TIL about the --dry-run flag, thanks for that tip!

Using your snippet as a base, I came up with a bash alias for this:

```
genpass() {
CHARS=${1:-32}

ITEM=$(op item create \
--dry-run \
--category Password \
--generate-password="letters,digits,symbols,$CHARS" \
--format json)

PASS=$(echo "$ITEM" | jq -r '.fields[] | select(.id == "password").value')

echo "$PASS"
}
```

That could all be one or two lines but I split it up for ease-of-use. 😅

Usage:
```
❯ genpass
7FwhRY.Zp.BVWxUrqUxKPEQQx-u!PKa.

❯ genpass 5
n3F-L

❯ genpass 64
ngtstGwJ3KmJQ2fJ-MkVkCPNNCqHXt_k-j3szo4KvVeFHVi*J*P*b2xVxpdRWRA8
```