Solve issue #2382

[francescoingv]

Overview

Enable the Processor to delete resources created when a job DELETE is submitted #2382

Related Issue / discussion

Solve issue #2382

Additional information

BaseProcessor: added hook remove_resources() to enable derived classes to handle removal of resources
PostgreSQLManager and TinyDBManager: modified delete_job() to call processor.remove_resources(job_id) when result files are removed.
DummyManager and MongoDBManager: do not modified as not handling result files

Dependency policy (RFC2)

• I have ensured that this PR meets RFC2 requirements

Updates to public demo

• I have ensured that breaking changes to the pygeoapi master demo server have been addressed
  • https://github.com/geopython/demo.pygeoapi.io/blob/master/services/pygeoapi_master/local.config.yml

Contributions and licensing

(as per https://github.com/geopython/pygeoapi/blob/master/CONTRIBUTING.md#contributions-and-licensing)

• I'd like to contribute [feature X|bugfix Y|docs|something else] to pygeoapi. I confirm that my contributions to pygeoapi will be compatible with the pygeoapi license guidelines at the time of contribution
• I have already previously agreed to the pygeoapi Contributions and Licensing Guidelines