This change fixes the pipeline behavior when producing targets:
* produce and extract now return rp_buffer, which has a start pointer
and size
* the python api `revng.api` will return on produce/extract either str
or bytes depending on the mime type of the container
* the GraphQL api will encode bytes in base64
Rework both classes in schema_generator.py, main changes:
* Drop manager.pipeline_artifact_structure as it was used exclusively
by SchemaGenerator and is no longer needed
* Rename SchemaGen and BindableGen to SchemaGenerator and
DynamicBindableGenerator to better express their role, add
docstrings that explain what they do
* Decouple Artifacts and Analyses discovery, since a step can have
analyses and no artifacts (and vice-versa)
When requesting a produce for multiple targets the result will be a
dictionary mapping "<target>:<result>". This also changes the GraphQL
API where a json-serialized string is returned.
Splits the module in 2:
* static_handlers: as the name suggests this is where handlers for
static endpoints (e.g. not dependent on the pipeline) are implemented
* schema_generator: this is where the schema is generated from a
manager's pipeline definition, together with the handler for the
autogenerated endpoint