Add Toroid device support and update WireMetadata for charge toroids

[kabanaty]

This pull request adds support for Toroid devices to the codebase, enabling their creation, management, and integration with existing device handling infrastructure. The main changes include the implementation of the Toroid class and its supporting classes, updates to the device reader logic, and minor enhancements to related metadata structures.

Toroid device support:

• Added a new Toroid class in slac_devices/toroid.py, along with supporting classes ToroidPVSet, ToroidControlInformation, and ToroidMetadata. These handle Toroid-specific process variables, control information, and metadata, and provide methods for accessing current and buffered TMIT values.
• Updated slac_devices/reader.py to import the new Toroid class and include "toroids" in the list of recognized device types and the device constructor map.

Device creation enhancements:

• Added a new create_toroid function to slac_devices/reader.py for instantiating Toroid devices by area and name, with error handling for invalid or missing data.

Metadata improvements:

• Extended the WireMetadata class in slac_devices/wire.py to include an optional charge_toroids field, allowing wire devices to reference associated Toroids.

[eloise-nebula]

Looks good. Just one comment. I'm approving. Thank you!