Switch events to properties

Right now there is an `events` property that returns a dictionary of what events are enabled. There are separate `enable_` and `disable_` functions for each event type. Instead, we should remove `events` in favor of a property for each event. To know if it is enable, then you can read it. To change it, the value can be set.

The 37x library should be updated to match. https://github.com/adafruit/Adafruit_CircuitPython_ADXL37x

Read the existing `events`, `enable_`, and `disable_` API in the ADXL34x library, then compare the corresponding implementation in the linked ADXL37x library. The work is complete when both libraries expose readable and settable properties for each event instead of the dictionary and separate functions.

Written by the indexing model from the issue text.