Get bbox query parameter interactively

[MTachon]

Overview

This PR implements a way for end-users to get interactively the bbox query parameter from a collection's HTML page. In order to get bbox coordinates, end-users can click and drag the mouse over a rectangular area of interest, while pressing the the Ctrl key. A popup appears with the bbox query parameter corresponding to the rectangular area drawn on the map. The popup's text can then be copied and pasted directly in the query URL.

Additional Information

Several provider types may support an additional bbox-crs query parameter that specify which coordinate reference system the bbox's coordinates are in. In the part 2 of the OGC API Features standard, it says that "If the bbox-crs parameter is not specified then the coordinate values of the bbox parameter SHALL be assumed to be in the default CRS specified in OGC API - Feature - Part 1: Core; that is http://www.opengis.net/def/crs/OGC/1.3/CRS84...". It is likely that other OGC API standards will use the same assumption. This implementation allows to get interactively the bbox query parameter directly in the default CRS. The bbox can therefore be used without specifying any bbox-crs.

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

[MTachon]

CI issues are not related to PR.