Make embedding cache and query cache optional

**Is your feature request related to a problem? Please describe.**
Currently the cache is mandatory, i.e. the cache has to at least be 1 in size.
Users must have the ability to turn the cache off by removing the settings.

**Describe the solution you'd like**
Make the cache be turned off when the settings are not present.

**Describe alternatives you've considered**
N/A

**Additional context**
N/A
