fix: Custom parameters validation

[kuipumu]

Description

This PR adds a fix to the validation of the LTI consumer XBlock custom parameters field. The previously merged PR https://github.com/openedx/xblock-lti-consumer/pull/392 introduced a bug that broke backwards compatible with custom parameters such has: ["next=something?repo=https://github.com/org/repo?folder=/home/user&branch=main"]. This issue was raised on https://github.com/openedx/xblock-lti-consumer/issues/410.

Type of Change

• [x] Modify CUSTOM_PARAMETER_REGEX constant.
• [x] Include tests for all modified code.

Testing:

1. Create a course and add a LTI consumer XBlock.
2. Add custom parameters to the XBlock settings.

["next=something?repo=https://github.com/org/repo?folder=/home/user&branch=main"] 

3. Go to the live course and execute an LTI launch.
4. The custom parameters should be present on the LTI launch data.

[openedx-webhooks]

Thanks for the pull request, @kuipumu! Please note that it may take us up to several weeks or months to complete a review and merge your PR.

Feel free to add as much of the following information to the ticket as you can:

• supporting documentation
• Open edX discussion forum threads
• timeline information ("this must be merged by XX date", and why that is)
• partner information ("this is a course on edx.org")
• any other information that can help Product understand the context for the PR

All technical communication about the code itself will be done via the GitHub pull request interface. As a reminder, our process documentation is here.

Please let us know once your PR is ready for our review and all tests are green.

[codecov[bot]]

Codecov Report

All modified and coverable lines are covered by tests :white_check_mark:

Comparison is base (07a8c26) 97.84% compared to head (dbc0590) 97.84%.

Additional details and impacted files

```diff @@ Coverage Diff @@ ## master #412 +/- ## ======================================= Coverage 97.84% 97.84% ======================================= Files 77 77 Lines 6696 6696 ======================================= Hits 6552 6552 Misses 144 144 ``` | [Flag](https://app.codecov.io/gh/openedx/xblock-lti-consumer/pull/412/flags?src=pr&el=flags&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=openedx) | Coverage Δ | | |---|---|---| | [unittests](https://app.codecov.io/gh/openedx/xblock-lti-consumer/pull/412/flags?src=pr&el=flag&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=openedx) | `97.84% <100.00%> (ø)` | | Flags with carried forward coverage won't be shown. [Click here](https://docs.codecov.io/docs/carryforward-flags?utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=openedx#carryforward-flags-in-the-pull-request-comment) to find out more.

:umbrella: View full report in Codecov by Sentry.
:loudspeaker: Have feedback on the report? Share it here.

[alangsto]

@kuipumu would you mind updating the version in https://github.com/openedx/xblock-lti-consumer/blob/master/lti_consumer/__init__.py? Thank you!

[kuipumu]

@alangsto Sure, just added a commit with an update to init and CHANGELOG.rst

[mphilbrick211]

Hi @alangsto! Are you able to merge this if it's good-to-go?

[mphilbrick211]

@kuipumu Hi there! Would you mind resolving the branch conflicts that have popped up?

@alangsto - is this something you can merge for us? Thanks!

[kuipumu]

@mphilbrick211 I resolved the conflicts and updated the version and changelog.

[mphilbrick211]

Thanks, @kuipumu! @alangsto this look ready for merge. Thanks!

[openedx-webhooks]

@kuipumu 🎉 Your pull request was merged! Please take a moment to answer a two question survey so we can improve your experience in the future.