[nextMajor] remove metadata conversion

[aryanA101a]

Fixes #188

[rgaudin]

@aryanA101a, thank you ; but:

• we still need to encode to bytes.
• if you remove code, you should remove associated test. This proves you didn't run the tests locally… well you should

FYI we'll only merge this once we want to release a new major version as this is an API break and we're in no rush to do so

[aryanA101a]

@rgaudin Sorry, my bad.
Actually, I ran the tests after the modification but didn't install the project.

[kelson42]

@aryanA101a Any update?

[rgaudin]

LGTM ;

Must NOT be merged!. This is an API break; we'll merge once we know we're ready to publish a major version

[rgaudin]

converted to draft to prevent accidental merge

[benoit74]

I don't think this is sufficient: type hints should be simplified as well to explicitly mention these methods support only bytes and str values now (i.e. conversion must be done by python-scraperlib or any other "user")

[rgaudin]

Thank you @benoit74 ; that's right and I forgot @aryanA101a to mention that you should not force-push after having asked for a review ; it makes (and made in that case) reviewing a real pain.

[rgaudin]

@aryanA101a please update type hints as suggested