Set gz tool name via GZ_CLI_EXECUTABLE_NAME

[scpeters]

🎉 New feature

Enable co-installability of gazebo-classic and gz-sim by allowing gz executable to be renamed

Summary

Currently gazebo-classic and gz-tools cannot be installed side-by-side since both install a gz executable. This pull request adds a cmake variable to customize the name of the gazebo-classic CLI tool to allow a customized package with a different tool name.

Test it

To rename gz to gz11 (for example), invoke cmake with -DGZ_CLI_EXECUTABLE_NAME=gz11

Checklist

• Signed all commits for DCO
• Added tests
• Added example and/or tutorial
• Updated documentation (as needed)
• Updated migration guide (as needed)
• Consider updating Python bindings (if the library has them)
• codecheck passed (See contributing)
• All tests passed (See test coverage)
• While waiting for a review on your PR, please help review another open pull request to support the maintainers

Note to maintainers: Remember to use Squash-Merge and edit the commit message to match the pull request summary while retaining Signed-off-by messages.

[j-rivero]

Does make sense to convert this to an option?

iff --git a/tools/CMakeLists.txt b/tools/CMakeLists.txt
index a0ec46236e..4bbf71ddf8 100644
--- a/tools/CMakeLists.txt
+++ b/tools/CMakeLists.txt
@@ -24,9 +24,7 @@ if (HAVE_DART)
   link_directories(${DART_LIBRARY_DIRS})
 endif()
 
-if ("${GZ_CLI_EXECUTABLE_NAME}" STREQUAL "")
-  set(GZ_CLI_EXECUTABLE_NAME "gz")
-endif()
+option(GZ_CLI_EXECUTABLE_NAME "Name for the cli tool (default gz)" "gz")
 
 if(NOT WIN32)
   # gz_TEST and gz_log_TEST use fork(), that is not available on Windows

[scpeters]

I had actually started with an option and then found out that options are only boolean

• https://cmake.org/cmake/help/latest/command/option.html

so I switched to this approach

[j-rivero]

Minor comment, looks good.