Remove xblockutils in favor of xblock.utils in main code

[Kelketek]

Description

This PR removes dependence on the deprecated xblockutils package in main code. It retains usage of the package in testing.

Supporting information

This block is pulling in XBlock-utils into openedx-platform. xblock-utils depends on web-fragments, which is currently being excised as a separate dependency.

Testing instructions

• Add this as a mount to tutor with tutor mounts add xblock-poll
• tutor dev stop && tutor dev start -d Restart seems finicky with mounts, so use stop and start.
• Remove the existing xblock poll by running pip uninstall xblock-poll in the LMS and CMS containers (tutor dev dc exec -it lms -- /bin/bash to enter the LMS, for instance)
• pip install /mnt/xblock-poll in both the CMS and LMS containers.
• tutor dev restart
• Add poll and survey to the advanced modules list of a course.
• Add both a poll and a survey block
• Try them out-- verify they seem to function as expected.

Deadline

ASAP

Other information

This change removes support for Quince and Python 3.11.

[pkulkark]

LGTM 👍

• I tested this: verified poll and survey components work as expected after this change.
• I read through the code.