Feature/pets management

[FeliGoblin]

Proposed change:

Adds pets to the integration!
Each pet is represented as a device with its own entities.

This includes pets created on the account that's signed in, as well as any pets from other account(s) that are linked/bound to any of your devices, including ones that are shared with you, by default. The inclusion of "shared pets" can be disabled in the integration settings.

It’s fairly simple for now, focusing on establishing the core structure. Future PRs will add support for creating and deleting pets, assigning them to devices, managing collars, etc.

Pets as devices:

Pets are added as a "service" type to visually differentiate them from actual devices, but this doesn't effect functionality at all from what I can tell.

Entities:

The Configuration input entities will update those details through the API.
"Shared pets" (pets from other accounts), can also be updated like this. I can't imagine they intended for people to be able to modify other people's pet's settings so I would argue this is an exploit of their API. So, I don't know if this is something we want to keep? It's also entirely possible this will be patched out in the future, whether that means pets from other accounts will be read-only or completely blocked I can't say.

Extra attributes:

The 'Linked Devices' entity includes the corresponding device entry IDs from your own Home Assistant, I imagine that could be handy for some creative automations.

The main pet entity includes some variables in their raw form, maybe someone could find some use for them, maybe not. 🤷‍♀️

A pet with a custom breed and no avatar assigned:

Closes #203 (issue)

Type of change:

• New device.
• Bug fix (non-breaking change which fixes an issue).
• New feature or enhancement (non-breaking change which adds functionality).
• Documentation only.
• Other (please explain).

Checklist:

• If applicable, I have added corresponding documentation changes.
• If applicable, I have reviewed the feature / enhancement guidlines before submitting my request.
• If applicable, I have tested my code for new features & regressions on the latest version of Home Assistant.

Additional notes:

Changes:

• Replaced uses of 'datetime.utcnow()' (deprecated) with homeassistant.util.dt.utcnow()
• Moved the 'PetlibroHub.loaded_device_sn' set to the DevicesHelper.
• Moved the 'PetlibroHub.feed_number_unique_ids' and 'PetlibroHub.unit_entities_unique_ids' dicts to the Unit_Entities helper.
• Changed 'PetlibroHub.devices' to a dictionary with serial numbers as keys.

New:

• Device serial numbers, device IDs and owned/shared status gets saved to Config Entry options.
• Pet IDs, pet device IDs and owned/shared status gets saved to Config Entry options.
• Added DevicesHelper.
• Added PetsHelper.
• Devices and Pets removed from the Petlibro account will be removed from the integration automatically.
• Added 'media' directory for images etc.
• Added option to Integration Settings:
  • Show Pets from Shared Devices
• Added entity platforms:
  • date
  • image
• Added methods to API:
  • device_get_bound_pets
  • pets.get_list
  • pets.get_details
  • pets.get_bound_devices
  • pets.save_or_update
  • pets.goal_setting
• Added Pet object and pet devices with entities.

I showed an option called "Include non-RFID Pet Consumption" in the issue post, I've removed it for now until I properly figure out how best to implement water intake as well as food, since they don't include RFID water intake in the member/pet/detailv2 API call like they do for food.

[jjjonesjr33]

Let's give it a try, will release as a pre-release to run tests on. Great work @FeliGoblin