Adding the ability to sample to a list of dictionaries

Add the ability to use the core sampler as a library to obtain everything in the database for a given project or EB. Usage looks like this:

sampler = CoreSampler(conn, format="dict")
list_of_tables_and_rows = sampler.sample_project("uid://evla/execblock/...").items

The returned items will look like this (in YAML format):

table_name:
  - column1: value1
    column2: value2
...

Or in Python, [{"execblocks": [{"column1": value1, ...}]}].