Add option for sorting most popular sessions

[lcduong]

This PR closes/references issue #161 . It does so by:

1. Add sort dropdown in session view
2. implement logic when sort with title/time/popularity

How has this been tested?

Checklist

• I have added tests to cover my changes.

[lcduong]

[sourcery-ai]

We have skipped reviewing this pull request. All of the files are larger than we can process. We're working on it!

[sourcery-ai]

We have skipped reviewing this pull request. Here's why:

• All of the files are larger than we can process. We're working on it!
• It looks like we've already tried to review the commit ff5943b in this pull request and failed.

[mariobehling]

Thank you. In the mobile view could you change the dropdown for popularity to an icon, please and move it in front of the "clear filters" icon similar to the previous eventyay version?

[odkhang]

Hi @mariobehling, updated as your request

[mariobehling]

Thank you. I also realized the "Add to Calendar" option is missing in the mobile version. Please add the icon into the mobile version (without the text "Add to Calendar" next to the version info.

[odkhang]

Hi @mariobehling, updated

[hongquan]

Where is the source of src/prhttps://bitbucket.org/hescar/markaz/pull-requests/155etalx/static/agenda/js/pretalx-schedule.js file? Its content in this PR looks like the output of bundle process, not the source.

[odkhang]

Where is the source of src/prhttps://bitbucket.org/hescar/markaz/pull-requests/155etalx/static/agenda/js/pretalx-schedule.js file? Its content in this PR looks like the output of bundle process, not the source.

Hi @hongquan, pretalx-shedule.js is bundle of this plugin fossasia/eventyay-talk-schedule#12

[hongquan]

The PR looks Ok, but unfortunately, it includes a code generated by fossasia/eventyay-talk-schedule#12, and the code in eventyay-talk-schedule PR is still in question, I cannot approve this PR yet.
But this PR is OK to merge if eventyay-talk-schedule PR is approved.