Move the last cache implementation to the influxdb3_cache crate

[hiltontj]

Problem

The code that implements the last cache is currently in the influxdb3_write crate. Since the influxdb3_write crate is contains a lot of code, and should be focused on the write buffer, the last cache does not need to be there.

Proposed solution

Move the code for the last cache to the influxdb3_cache crate, which was created for the metadata cache.

Alternatives

N/A

Additional context

N/A