[BUG] `do_lowercase_strings` is being applied to all property values by default

[bechbd]

Describe the bug All the string properties are being lowercased due to the do_lowercase_strings normalization being applied

To Reproduce Given the configuration below:

- implementation: nodestream.interpreting:Interpreter
  arguments:
    interpretations:
      - type: source_node
        node_type: Artist
        key:
          id: !jmespath nconst
        properties:
          name: !jmespath primaryName

All the name properties are being lowercased due to the do_lowercase_strings normalization being applied. This is an unexpected behavior from a CX perspective.

Expected behavior The string values are not changed

Additional context This also happens to key properties but I see the logic here in lowercasing all key values, to ensure consistency in key lookups so that does not need to change.