Improve ISM init script

[AlexRuiz7]

Related issue
wazuh/wazuh-indexer#56

Description

This PR fixes a bug in the ISM init script, and improves its logging to make it clearer and easier to debug.

Logs example

See wazuh/wazuh-indexer#56 (comment)

Tests

• Build the package in any supported platform
  • Linux
  • Windows
  • macOS
  • Solaris
  • AIX
  • HP-UX
• Package installation
• Package upgrade
• Package downgrade
• Package remove
• Package install/remove/install
• Change added to CHANGELOG.md

• Tests for Linux RPM
  • Build the package for x86_64
  • Build the package for i386
  • Build the package for armhf
  • Build the package for aarch64
  • %files section is correctly updated if necessary
• Tests for Linux deb
  • Build the package for x86_64
  • Build the package for i386
  • Build the package for armhf
  • Build the package for aarch64
  • Package install/remove/install
  • Package install/purge/install
  • Check file permissions after installing the package
• Tests for macOS
  • Test the package from macOS Sierra to Mojave
• Tests for Solaris
  • Test the package on Solaris 10
  • Test the package on Solaris 11
  • Check file permissions on Solaris 11 template
• Tests for IBM AIX
  • %files section is correctly updated if necessary
  • Check the changes from IBM AIX 5 to 7