FlatGeoBuf: ArrowStream: return a released array when there are no rows

[rouault]

Fixes #8509

@jorisvandenbossche
I've decided to uniformize the behavior of all drivers to immediately return a released array when there are no rows. The GeoPackage one was for example returning a non-released empty batch at the first iteration and then a released batch.

[jorisvandenbossche]

That sounds good, I don't think it's important (or useful) to return an empty batch instead of no batch at all

[coveralls]

coverage: 67.684% (-0.001%) from 67.685% when pulling 15bf9a1 on rouault:fix_8509 into f0095ee on OSGeo:master.

[rouault]

The backport to release/3.7 failed:

The process '/usr/bin/git' failed with exit code 1

stderr

error: could not apply 98f923872e... GPKG: ArrowStream: immediately return a release array when there are no rows (refs #8509)
hint: After resolving the conflicts, mark them with
hint: "git add/rm <pathspec>", then run
hint: "git cherry-pick --continue".
hint: You can instead skip this commit with "git cherry-pick --skip".
hint: To abort and get back to the state before "git cherry-pick",
hint: run "git cherry-pick --abort".

stdout

Auto-merging autotest/ogr/ogr_flatgeobuf.py
Auto-merging ogr/ogrsf_frmts/flatgeobuf/ogrflatgeobuflayer.cpp
[backport-8512-to-release/3.7 f38fffc1b5] FlatGeoBuf: ArrowStream: return a released array when there are no rows (fixes #8509)
 Author: Even Rouault <even.rouault@spatialys.com>
 Date: Tue Oct 3 12:10:01 2023 +0200
 2 files changed, 25 insertions(+), 1 deletion(-)
Auto-merging autotest/ogr/ogr_gpkg.py
CONFLICT (content): Merge conflict in autotest/ogr/ogr_gpkg.py
Auto-merging ogr/ogrsf_frmts/gpkg/ogrgeopackagelayer.cpp
Auto-merging ogr/ogrsf_frmts/gpkg/ogrgeopackagetablelayer.cpp

To backport manually, run these commands in your terminal:

# Fetch latest updates from GitHub
git fetch
# Create a new working tree
git worktree add .worktrees/backport-release/3.7 release/3.7
# Navigate to the new working tree
cd .worktrees/backport-release/3.7
# Create a new branch
git switch --create backport-8512-to-release/3.7
# Cherry-pick the merged commit of this pull request and resolve the conflicts
git cherry-pick 1e2917cfd3cd2528647ef45aaec904e36f708203,98f923872e1ad74ff66eb720c1c42af63f79d7ee,15bf9a19a67c6670d82afacf473dd5298cc451cb
# Push it to GitHub
git push --set-upstream origin backport-8512-to-release/3.7
# Go back to the original working tree
cd ../..
# Delete the working tree
git worktree remove .worktrees/backport-release/3.7

Then, create a pull request where the base branch is release/3.7 and the compare/head branch is backport-8512-to-release/3.7.

[rouault]

manually backported to 3.7 in ce1eca1, 48f46f8 and 3d0ba02