Add simple interface to create and send common telegrams

[farmio]

The current minimal example for sending a simple telegram to a group address is quite involved. It needs a lot of imports and knowledge about inner workings of xknx.

import asyncio

from xknx import XKNX
from xknx.dpt import DPTArray
from xknx.telegram import GroupAddress, Telegram
from xknx.telegram.apci import GropupValueWrite


async def main():
    async with XKNX() as xknx:
        await xknx.telegram_queue.put(
            Telegram(
                destination_address=GroupAddress("1/1/1"),
                payload=GropupValueWrite(DPTArray([1])),
            )
        )


asyncio.run(main())

I propose to add a helper class abstracting this from users. It could be in a similar way to HA knx.send service.
This could look something like this:

import asyncio

from xknx import XKNX


async def main():
    async with XKNX() as xknx:
        await xknx.groups.write(
            address="1/2/3",
            value=21.5,
            value_type="temperature",
        )


asyncio.run(main())

I was thinking about adding

• write
• respond
• read (waiting for response)
• read (just send)

---

I'd love to hear some further ideas or naming and interface proposals.

[farmio]

#1027