utils.EncodedId() has basically the same functionalityy of using
utils._url_encode(). So remove utils._url_encode() as we don't need
it.

Add EncodedId string class. This class returns a URL-encoded string
but ensures it will only URL-encode it once even if recursively
called.

Also added some functional tests of 'lazy' objects to make sure they
work.

Make sure all usage of the ID in the URL path is encoded. Normally it
isn't an issue as most IDs are integers or strings which don't contain
a slash ('/'). But when the ID is a string with a slash character it
will break things.

Add a test case that shows this fixes wikis issue with subpages which
use the slash character.

Closes: #1079

fix(api): services: add missing `lazy` parameter

Commit 8da0b758c589f608a6ae4eeb74b3f306609ba36d added the `lazy`
parameter to the services `get()` method but missed then using the
`lazy` parameter when it called `super(...).get(...)`

Closes: #1828

fix: broken URL for FAQ about attribute-error-list

The URL was missing a 'v' before the version number and thus the page
did not exist.

Previously the URL for python-gitlab 3.0.0 was:
https://python-gitlab.readthedocs.io/en/3.0.0/faq.html#attribute-error-list

Which does not exist.

Change it to:
https://python-gitlab.readthedocs.io/en/v3.0.0/faq.html#attribute-error-list
  add the 'v' --------------------------^

See https://docs.gitlab.com/ee/api/group_access_tokens.html

chore: add `pprint()` and `pformat()` methods to RESTObject