Add new loading mechanism for GeoIP context

[balavinaithirthan]

1. We added an additional loader to the GeoIP plugin to allow for users to create an empty context, load data in later, and replace contexts through data loads. The loader allows for the original V1 loader to still work because it loads the V1 context into memory and on save converts it to a V2 context. The context save context_name should not be used alone because an implicit writing sink is added to the end; instead it should continue being used to pipe data into context load.

Questions:

1. Is it possible to rebase onto main with the tensor-plugins submodule conflict?

[dominiklohmann]

Awesome, thanks for this! I think this is a very solid improvement to the geoip context usability.