Tuya Climate support Enum for Eco/Sleep Mode

**Describe the problem you have/What new integration you would like**

Some Tuya thermostats use Tuya's 'mode' instruction set for Eco Mode and Sleep Mode (https://developer.tuya.com/en/docs/iot/f?id=K9gf45ld5l0t9). That is an Enum data type.

I think it would be great if Tuya Climate supported something like
```
climate:
- platform: tuya
...
working_mode:
eco:
datapoint: 8
off_value: 0
on_value: 1
sleep:
datapoint: 7
off_value: 0
on_value: 1
```
which would then function the same as `preset: eco:` or `preset: sleep:`.

**Please describe your use case for this integration and alternatives you've tried:**

I'm using `fan_mode` as a workaround since it supports Enum.

**Additional context**

Personally, I'm only interested in the eco option. I just thought I should include the sleep option since that is the same situation and could arise in the future.

Review the Tuya Climate integration and compare its existing preset and fan_mode handling with the proposed YAML shape. Confirm how Enum datapoints should map to eco and sleep controls; done means both modes can be configured and behave like the corresponding presets, with tests covering the configuration.

Written by the indexing model from the issue text.