Fix importing '+proj=topocentric ... +type=crs' by using a geocentric CRS as the base CRS

[rouault]

Fixes https://lists.osgeo.org/pipermail/proj/2023-October/011153.html

[ErixenCruz]

Thank you for getting back about this so quickly

[rouault]

The backport to 9.3 failed:

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

stderr

error: could not apply 451a2a48... Fix importing '+proj=topocentric ... +type=crs' by using a geocentric CRS as the base CRS
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/iso19111/io.cpp
Auto-merging test/cli/testvarious
CONFLICT (content): Merge conflict in test/cli/testvarious
Auto-merging test/cli/tv_out.dist
CONFLICT (content): Merge conflict in test/cli/tv_out.dist
Auto-merging test/unit/test_io.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-9.3 9.3
# Navigate to the new working tree
cd .worktrees/backport-9.3
# Create a new branch
git switch --create backport-3924-to-9.3
# Cherry-pick the merged commit of this pull request and resolve the conflicts
git cherry-pick 451a2a48d3ec461b56094cce623f9f91c5c457bf
# Push it to GitHub
git push --set-upstream origin backport-3924-to-9.3
# Go back to the original working tree
cd ../..
# Delete the working tree
git worktree remove .worktrees/backport-9.3

Then, create a pull request where the base branch is 9.3 and the compare/head branch is backport-3924-to-9.3.

[rouault]

cherry-picked in 9.3 per 72de8f7