Serialize all NumPy integer, float and bool scalars in json_serial

[Shubham-Padkonde]

json_serial only recognised int32, int64, float32 and float64 by type name, so other NumPy scalars that providers commonly return (e.g. uint8 or int16 nodata/fill values, float16 data, bool) raised "TypeError: ... not serializable". Match on NumPy's abstract integer and floating types (and bool) instead, still without importing NumPy.

Overview

Related Issue / discussion

Additional information

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