v.in.wfs : Migration to OWSLib based web service requests

[karunakar2]

The python code of v.in.wfs uses Urllib and fetches features based on updating the wfs_url. OWSLib can be utilised for the purpose.

Modify the code to:
The code is updated to use OWSLib for web service requests in v.in.wfs and caters to the ToDo item / Enhancement in the code.

Prior code:

1. wfs_url is modified to construct WFS requests

Proposed code:

1. OWSlib functions are used to get capabilities and features
2. variables are used to adapt to the option variables.

Note:
There is a need to update on the code against options["name"] and options["layer"] for uniformity; Suggestions welcome.
Attempting my first pull request in the space, request you to comment to update where necessary.

[petrasovaa]

Thanks for your contribution! I am not super familiar with this tool, so maybe someone else can comment here. Since OWSlib is not a required dependency, it needs to imported this way to ensure CI will work. See also the rest of the guide to make sure the formatting conforms to our style.

Is this adding new functionality or just replacing the previous one?

[karunakar2]

Hi @petrasovaa thanks for looking into this.
Will update per comments.

There was a todo item in the code to use OWSLib and the current code tries to incorporate it. Not new functionality per se.

[petrasovaa]

@HamishB would you mind reviewing this, since you put the TODO in there?

[karunakar2]

#4275 for relevant issue and testing.

[ninsbl]

Would URL quoting (https://docs.python.org/3/library/urllib.parse.html#urllib.parse.quote) be an alternative to a new - optional - dependency with owslib?