Fix: Translate links in table column headers

in column headers.

correctly in the LMS.

Simplify get_message: Return message instead of template

Instructor Tool: Support searching for answers from multiple users

Add unit tests for instructor tool

field containers.

previous PR (https://github.com/open-craft/problem-builder/pull/47).

The new tests check if:

- preferred block attrs are used when building block tree for current course
- block tree excludes pb-choice blocks
- blocks are correctly marked as (in)eligible
- new-style keys are handled correctly
- student_view passes calls rendering method with correct template args
- author_view and studio_view show appropriate messages

Don't cause a 500 error in the LMS if get_block unexpectedly returns None

Add an extra selector to fix CSS rule ambiguity

Fix two bugs (OC-839)

Allow toggling show_title behaviour during upgrade (OC-805)

Fix JS bug when HTML block is followed by an answer block

Visual improvements to Table block.

Instructor Tool: Drop-down for "Root block ID" section, pagination improvements (OC-783)

if "question" attribute is not set to a meaningful value.

set on block.

This ensures that export results correctly reflect changes to answers
associated with Long Answer blocks.

it works for non-eligible blocks with empty "Question title" (display_name).

InstructorToolBlockWithMixins" error that gets thrown when trying to
edit Instructor Tool blocks in Studio.