feat: add sc api to manage facts

[MasterOdin]

PR adds an API for managing facts in the semantic catalog so that you can:

1. add a fact
2. drop an existing fact
3. edit an existing fact

The expectation would be that for (1) and (3) that the end user would run the vectorize function afterwards.

Assuming we're fine with this, I'd then go to add API for objects and sql examples, but wanted to start with just one for now.