Replace extra-data with repackaging of the archive

JetBrains allows Flathub to repackage their IDEs as long as there are no changes to the contents:

> Thanks for raising this, and sorry it took us a while to get back.
We’re fine with Flathub redistributing JetBrains IDE installation archives as long as this follows the current model: no changes to the archive content themselves, just repackaging.
If someone from the Flathub team needs this approval in another form or has follow-up questions, feel free to reach out. Thanks again.
[YouTrack Issue](https://youtrack.jetbrains.com/issue/IJPL-179853/Grant-Flathub-permission-to-redistribute-JetBrains-IDEs#focus=Comments-27-13624931.0-0)

Please consider to package the whole archive at build time to replace the extra-data download. Reasons for this change are given in the [YouTrack Issue](https://youtrack.jetbrains.com/issue/IJPL-179853/Grant-Flathub-permission-to-redistribute-JetBrains-IDEs).

Start by locating the current extra-data configuration and the build setup for the JetBrains archive. Read the linked YouTrack issue for the stated reasons and packaging constraints. Done means the whole archive is packaged at build time, the extra-data download is removed, and the archive contents remain unchanged.

Written by the indexing model from the issue text.