esp32-cam send snapshot over mqtt (enabling deep sleep usage)

**Describe the problem you have/What new integration you would like**
Produce function to take snapshot and send it to mqtt topic.
(Similar to what frigate uses) To be used by Home Assistant Mqtt Camera component - https://www.home-assistant.io/integrations/camera.mqtt/

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

**Additional context**
Use this together with deep sleep function. This way, it’s possible to send a picture every 10m or so, thus reducing power consumption and allowing camera to be battery operated.

Start with the linked Home Assistant MQTT Camera documentation and inspect the existing ESP32-CAM and deep-sleep integrations in the implementation repository. Define how a snapshot is captured and published to an MQTT topic, then verify that the resulting message can be consumed by Home Assistant and supports the requested periodic deep-sleep use case.

Written by the indexing model from the issue text.