Add SwOS password change support and refine PoE field mappings

[Lo0rd3]

Summary

• Add set_password() with SwOS password encoding (RC4-based)
• Expose password endpoint in field maps for SwOS/SwOS Lite
• Update SwOS PoE field mappings (incl. PoE standard) and mark LLDP fields optional where unsupported for CRS328-24P-4S+

-ps: im a intern still, this is my first commit for a public repo, sorry if i did something wrong!

[lanrat]

Thanks for this, and welcome — the password encoding is exactly right, which is the hard
part. I verified it against the JS in webui_reference/ and on two switches.

One bug: set_password() hardcodes {pwd:'...'}, but that's the SwOS field name. SwOS
Lite uses i01. Confirmed on hardware — pwd gets a 200 on a CRS309 (SwOS 2.18) and a 405
on a CSS610-8P (SwOS Lite 2.21), and i01 does the exact opposite. So as written it fails
on every SwOS Lite device. I've moved the field name into the field maps and merged the
password commit with that fix, plus length/ASCII validation to match what the web UI
enforces.

I held the PoE commit (343580c) back for now. It's probably right — the values it
replaces were explicitly labeled guesses — but I have no PoE-capable SwOS device, so I
can't check the field names the way I could for the password.

Could you grab the web UI source off the CRS328-24P-4S+ and add it to webui_reference/?
Same files as the other devices there (index.html, and engine.js if it's a separate
file). That's how I verified the password split, and it'd let me confirm the PoE mappings
the same way — then the commit goes straight in.

[lanrat]

I'm closing this for now. but if I could get a copy of the web resources for a CRS328-24P-4S+ (just attach them to this thread) I can re-visit the PoE mappings.