Better support of cooling mode for thermostats

[atsju]

I don't have the knowledge to fix this myself but here is a breakdown of my findings.

zha deduces the supported hvac_modes from the zigbee cluster/attribute thermostat_cluster_handler/ctrl_sequence_of_oper

zha/zha/application/platforms/climate/__init__.py

Line 268 in ebb6d89

def hvac_modes(self) -> list[HVACMode]:

zha/zha/application/platforms/climate/const.py

Line 150 in ebb6d89

SEQ_OF_OPERATION = {

Problem is that the attribute can be set to heating_only by manufacturer but this doesn't mean the thermostat cannot be set to cooling mode.
Ideally, there would be a way to try all "ctrl_sequence_of_oper" and "all system_mode" attributes of the ZCL to see what is actually supported by the thermostat.

There are other related issues that would benefit from this like zigpy/zha-device-handlers#2707
zigpy/zha-device-handlers#3587
and probably more https://github.com/zigpy/zha-device-handlers/issues?q=is%3Aissue+is%3Aopen+thermostat++cool