Add thermostat example (CON-1873)

[Cptmeme]

Description

I have made a thermostat example from already existing air conditioner example code.

Related

Fixes #1591

Testing

Tested compilation of esp32, esp32c6 and esp32h2, and tested connection to matter controller (homekit) using esp32c6.

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Checklist

Before submitting a Pull Request, please ensure the following:

• 🚨 This PR does not introduce breaking changes.
• All CI checks (GH Actions) pass.
• Documentation is updated as needed.
• Tests are updated or added as necessary.
• Code is well-commented, especially in complex areas.
• Git history is clean — commits are squashed to the minimum necessary.

As this is my first pull request, please let me know if I did anything wrong or out of the ordinary.

[CLAassistant]

All committers have signed the CLA.

[shubhamdp]

The only difference would be the data model right? We are doing the same thing already in the all_device_type_app.

esp-matter/examples/all_device_types_app/main/esp_matter_console_helpers.cpp

Lines 262 to 267 in eb5b9ad

	case ESP_MATTER_THERMOSTAT: {
	esp_matter::endpoint::thermostat::config_t thermostat_config;
	thermostat_config.thermostat.feature_flags = cluster::thermostat::feature::auto_mode::get_id();
	endpoint = esp_matter::endpoint::thermostat::create(node, &thermostat_config, ENDPOINT_FLAG_NONE, NULL);
	break;
	}

See, we can have an example for each device type, but then the maintenance becomes an overhead. We need to keep in mind about every example when updating things.

[Cptmeme]

I guess thats true, however I would have liked to have this example before I had to resort to converting other examples. I mean the all matter devices example is very nice, but not very beginner friendly. Having an example that just compiles makes it more accessible to less code savvy people (like me). Especially for the more common device types (like a light, a switch, a thermostat or blinds), I think it is nice to have ready made examples.