[14.0][IMP] datev_export_xml: Improve handling and download of bigger files

[fkantelberg]

Currently when big files are handled the server might respond with 500 MemoryError when opening the list or form view of the datev xml exports. The worker processes are hitting the RAM limits and will be killed.

[fkantelberg]

@tv-openbig Can you have a look at this PR? Usually it happens with 1GB files which could be hard to generate in the runboat.

The PRs #159 #160

[fkantelberg]

@tv-openbig
I developed the packaging for 14.0. I still need to forward port and test it in 15.0 and 16.0 (don't merge those PRs).

The migration should automatically convert from single file to multiple files per datev export. There is also an indicator in the top right now (exported/total) and the cron only exports invoices not yet exported (e.g. you can delete a specific package to regenerate it without setting everything back to draft). Setting the export to draft will remove all packages. I hope this workflow fits.

[fkantelberg]

@tv-openbig Also was faster than expected. I also finished the changes in 15.0 and 16.0.

[tv-openbig]

@fkantelberg Do you know why the runboat build failed ?

[fkantelberg]

No clue. was running before but got broken over the last weeks

[tv-openbig]

@fkantelberg

The splitting into two .zip archives does not work as expected.

My use case on the linked runbot:
1.) i configured a limit of 20MB

2.) I uploaded 11 invoices with each invoice one attachment of file size 2.5 MB

3.) I completed the created supplier bills and created a export of supplier bills

4.) Here is the list view of the invoices included in the test:

5.) Everything works fine so far, however i would expect due to my limitation a second .zip archive:

[fkantelberg]

@tv-openbig The file is slightly over 20mb and you have compression at work here which might fit. Please create a few more invoices.

[tv-openbig]

@fkantelberg Now it works. Thanks a lot.

[tv-openbig]

/ocabot merge patch

[OCA-git-bot]

This PR looks fantastic, let's merge it!
Prepared branch 14.0-ocabot-merge-pr-158-by-tv-openbig-bump-patch, awaiting test results.

[OCA-git-bot]

Congratulations, your PR was merged at b567637. Thanks a lot for contributing to OCA. ❤️