Ignition: bump ign-cmake2 and gazebo11 and add ignition-fuel-tools to Buster.

[chapulina]

Follow-up to #112

It's still failing to install ignition-edifice on Focal:

The following packages have unmet dependencies:
 ignition-edifice : Depends: libignition-cmake2-dev (>= 2.7.0) but 2.6.2-1~focal is to be installed
                    Depends: libignition-common4-dev but it is not going to be installed
                    Depends: libignition-fuel-tools6-dev but it is not going to be installed
                    Depends: libignition-gazebo5-dev but it is not going to be installed
                    Depends: libignition-gui5-dev but it is not going to be installed
                    Depends: libignition-launch4-dev but it is not going to be installed
                    Depends: libignition-math6-dev (>= 6.8.0) but 6.7.0-1~focal is to be installed
                    Depends: libignition-math6-eigen3-dev (>= 6.8.0) but it is not going to be installed
                    Depends: libignition-msgs7-dev but it is not going to be installed
                    Depends: libignition-physics4-dev but it is not going to be installed
                    Depends: libignition-plugin-dev (>= 1.2.0) but 1.1.0-1~focal is to be installed
                    Depends: libignition-rendering5-dev but it is not going to be installed
                    Depends: libignition-sensors5-dev but it is not going to be installed
                    Depends: libignition-tools-dev (>= 1.1.0) but 1.0.0-1~focal is to be installed
                    Depends: libignition-transport10-dev but it is not going to be installed
                    Depends: libignition-utils1-cli-dev but it is not going to be installed
                    Depends: libignition-utils1-dev but it is not going to be installed
                    Depends: libsdformat11-dev but it is not going to be installed
E: Unable to correct problems, you have held broken packages.

I narrowed it down to

libignition-utils1-dev : Depends: libignition-cmake2-dev (>= 2.7.0~pre1) but 2.6.2-1~focal is to be installed

I think 2.8.0 may have already been out when we the import job was run, which made 2.7 not be pulled and we were stuck with the old 2.6.2.

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It would be nice to improve this process 🙃 I actually don't know if just pulling ign-cmake2 will be enough, so this may not even be the end of this round.

The only suggestion I have is to always pull the latest versions of all libraries (abuse those globs!). I know there's a desire to keep track of what exact versions are being imported, but as noted along this series of PRs (#109 / #110 / #111 / #112), the versions listed on this file aren't accurately reflecting the state of the server.

If we always pull the latest versions:

• We're sure they all work together, because that's actively tested by the Ignition team
• We don't need to edit this file every time we need to make an upgrade (saves time)

[chapulina]

To make things even more interesting, I see some ign-cmake2 2.8.0 packages here, how did they get there? 😢 http://packages.ros.org/ros2/ubuntu/pool/main/i/ignition-cmake2/

[nuclearsandwich]

I created #115 to keep the process improvements discussion alive while we address the immediate issues.

[nuclearsandwich]

I had to make a small fixup to account for the fact that gazebo11 has been bumped to 11.5.1 as well. Merging this to rebase #114 and perform another import.