Added webhook support

[helto4real]

Breaking change

Proposed change

Make a trigger template webhook sensor in HA plus some cleanup

template:
  - trigger:
      - platform: webhook
        webhook_id: my-super-secret-id
    sensor:
      - name: "NetDaemon webhook temp sensor"
        state: "{{ trigger.json.temperature }}"
        unit_of_measurement: °C

Use following code to trigger it:

public record TriggerData
{
   [JsonPropertyName("temperature")]
   public double Temperature { get; set; }
}

var data = new TriggerData {Temperature=4.3};
// trigger using record
await client.TriggerWebhook("my-super-secret-id", data);
// trigger using anon type
await client.TriggerWebhook("my-super-secret-id", new {temperature = 4.1});

Type of change

• Dependency upgrade
• Bugfix (non-breaking change which fixes an issue)
• New feature (which adds functionality to an existing integration)
• Breaking change (fix/feature causing existing functionality to break)
• Code quality improvements to existing code or addition of tests

Additional information

• This PR fixes or closes issue: fixes #
• This PR is related to issue:
• Link to documentation pull request:

Checklist

• The code change is tested and works locally.
• Local tests pass. Your PR cannot be merged unless tests pass
• There is no commented out code in this PR.
• I have followed the [development checklist][dev-checklist]
• The code compiles without warnings (code quality chek)
• Tests have been added to verify that the new code works.

If user exposed functionality or configuration variables are added/changed:

• Documentation added/updated for www.home-assistant.io