[WFS provider] Include namespace prefix and URI in FILTER ...

[rouault]

computed from setSubsetString() when a namespace is declared on <wfs:FeatureType in GetCapabilities response

Fixes #49121

Follow-up to #43957 / PR #45043

[pathmapper]

Confirmed this fixes #49121, thanks!

[qgis-bot]

The backport to queued_ltr_backports failed:

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

stderr

error: could not apply f9cd2aab76... [WFS provider] Include namespace prefix and URI in FILTER ...
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 src/core/qgsogcutils.cpp
CONFLICT (content): Merge conflict in src/core/qgsogcutils.cpp
Auto-merging src/core/qgsogcutils.h
Auto-merging src/providers/wfs/qgswfsfeatureiterator.cpp
CONFLICT (content): Merge conflict in src/providers/wfs/qgswfsfeatureiterator.cpp
Auto-merging src/providers/wfs/qgswfsprovider.cpp
Auto-merging src/providers/wfs/qgswfsprovider.h
Auto-merging src/providers/wfs/qgswfsshareddata.cpp
Auto-merging tests/src/python/test_provider_wfs.py
CONFLICT (content): Merge conflict in tests/src/python/test_provider_wfs.py

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-queued_ltr_backports queued_ltr_backports
# Navigate to the new working tree
cd .worktrees/backport-queued_ltr_backports
# Create a new branch
git switch --create backport-50249-to-queued_ltr_backports
# Cherry-pick the merged commit of this pull request and resolve the conflicts
git cherry-pick f9cd2aab76809a5591fc54cf41c880af231d100d
# Push it to GitHub
git push --set-upstream origin backport-50249-to-queued_ltr_backports
# Go back to the original working tree
cd ../..
# Delete the working tree
git worktree remove .worktrees/backport-queued_ltr_backports

Then, create a pull request where the base branch is queued_ltr_backports and the compare/head branch is backport-50249-to-queued_ltr_backports.