when yielding data from a resource, mark given value to be normalized

[rudolfix]

Goal
We want to mark certain string values to be normalized according to naming convention used later in the pipeline. Compare such feature to dlt.with_table where we mark whole dictionary to be routed to table with given type.

Motivation
Quite often some lineage metadata is loaded with the data itself. For example in case of pipedrive we load a table with definitions of user defined fields. Those fields are present in dlt schema and their names are normalized like any other column names.

Tasks

1. • add normalize function in dlt.mark module. that will wrap a str in a string like object that will be serialized in typed_dump as a special type (like for example Decimal or datetime)
2. • when deserialized in normalizer, a normalize_identifier method from the current schema context will be applied to the value