Add config flow and yaml reload

[Snuffy2]

Features

• Add a config_flow to create new Momentary Switches
  • The settings/options for Momentary Switches created by config_flow can be changed in the Options
• Continue to support YAML based Momentary Switches
• Allow a Momentary Switch to be associated with another device
• Allow for Reload of the YAML based Momentary Switches from the Developer Tools so changes can be made without restarting HA
  • While not a standalone separate config file, it still allows for YAML based momentary switches that can be changed without needing to restart HA

Note

• It is likely that existing Momentary Switches will get new entity ids on first update. I'm not sure I'll be able to avoid this.
• I did not implement the ! entity id naming functionality in the YAML or in the config_flow
• No support for combining multiple Momentary Switches into a device.
• The Slovak language strings are 100% AI generated so likely need to be refined

---

This pull request refactors and modernizes the momentary Home Assistant integration, focusing on simplifying configuration management, improving code clarity, and enhancing the options flow. The changes remove legacy YAML config support, unify configuration handling via the UI and YAML import, and update service registration and device management logic.

Configuration Management and Refactoring:

• Replaced legacy YAML configuration logic with a unified approach that processes YAML via a reload service and handles all configuration through the same flow. Simplified initialization and entry setup in __init__.py and removed legacy device registry logic.
• Consolidated constants and removed unused helpers from const.py, defining only the necessary configuration keys and defaults.

Options Flow and UI Improvements:

• Redesigned the config flow in config_flow.py to use a unified schema builder for user input, supporting both UI and YAML import. Added a new options flow handler for config entries, allowing users to update options except for YAML-created switches.
• Improved validation and normalization of user input, including handling of toggle duration, mode selection, and device association.

Service Registration and Device Management:

• Added a reload service for the integration to allow YAML configuration to be reprocessed on demand. Updated device removal logic to use Home Assistant helpers, ensuring stale devices are cleaned up when entries are unloaded.

Fixes #54

[Snuffy2]

I fixed the issues with the duplicate entities by redoing the unique_id generation and standardized to storing the toggle_for as a HA duration dict.

[twrecked]

I just tried this and the upgrade failed, none of my existing devices got brought in. It shows them all as "no longer provided by the momentary component".

I tried to delete the entries but I can't seem to see a way to add a YAML file back into the component.

This is one of the files that failed to upgrade. It has a bunch of triggers I used to test my system.

version: 1
switches:
- name: +bad weather check trigger
  toggle_for: 1
- name: +change alarm to away
  toggle_for: 1
- name: +change alarm to disarmed
  toggle_for: 1
- name: +change alarm to emergency
  toggle_for: 1
- name: +change alarm to home
  toggle_for: 1
- name: +change automations to running
  toggle_for: 1
- name: +change automations to stopped
  toggle_for: 1
- name: +change cameras to away
  toggle_for: 1
- name: +change cameras to disarmed
  toggle_for: 1
- name: +change cameras to home
  toggle_for: 1
- name: +change phase to daytime
  toggle_for: 1
- name: +change phase to evening
  toggle_for: 1
- name: +change phase to nighttime
  toggle_for: 1
- name: +everybody left check trigger
  toggle_for: 1