[WIP] core/ap: dsa config: fix nasty roaming bug

[spolack]

replaces #1174

Still needs bisecting if and which of the following lines can be dropped:

• 3: option vlan_filtering '1'
• 4: option ports '{{ dsa_ports|join(' ') }}'
• 11: {{ portmapping.append(port|string + (":t" if tagged else ":u*")) }}
• 14-21 ...

[PolynomialDivision]

What about merging this as it is and later removing the unneeded stuff. Currently, I always need to cherry-pick the commits to have a working roaming setup because main is broken as you know. I would prefer a working config with maybe to much config over a broken one on main.

[spolack]

Fix doesnt work for me, seeing stale MAC Entries again, this time on the Switch interface...