windows shell init files use executable name

[Klaim]

• shell-init: Windows bat paths are factorized and depend on exe name (micromamba or mamba) except for mamba_hook.bat which for now needs to keep that name whatever the exe name;
• Fixed windows version detection: When more than one line of output appears at the start of cmd (because of AUTORUN), we parsed only the first line which failed the version detection. This version simply search every line instead of just the first one.
  It also clarifies through more precise logs the exact reason why enabling long-paths actually failed.
• Improved error output for clarity on failure to create shell-init files (.bat) or directories.