i2c Driver Docs

The driver APIs have been clearly divided into master and slave, with all calls now separated into i2c_master_* and i2c_slave_*. This provides a higher-level interface for the i2c driver. To support async operations in master mode, callbacks can be set in transmit, transmit_receive, and receive to signal when the operation is complete. An event callback can also be registered with register_event_callbacks to receive events such as I2C_EVENT_ALIVE, I2C_EVENT_DONE, and I2C_EVENT_NACK. To initiate a receive job call slave_receive while in slave mode and to wait for any receive data a callback can be registered with register_event_callbacks.

Changes to current i2c impl

• Add AsyncI2cSlaveDriver
• Add I2cBusDriver: allows adding I2cDevice
• Add I2cDevice: exposes read, write, read_write
• Add AsyncI2cBusDriver: allows adding AsyncI2cDevice (adds a guard that only one device can use the bus at once), cannot depend on I2cBusDriver because config of bus requires config of cmd queue depth for async operations
• Add AsyncI2cDevice: exposes async read, async write, async read_write
• add cfg guards for current esp calls major == 4 || version == 5.1
• add cfg guards to new calls major != 4 && version != 5.1

Challenges

• new i2c API does not expose transactional operations

### Tasks
- [ ] https://github.com/esp-rs/esp-idf-sys/pull/290