Removed all errors/warnings pointed out by hadolint version 2.7.0, except for the following
ignored rules:
- "DL3008 warning: Pin versions in apt get install"
- "DL3041 warning: Specify version with `dnf install -y <package>-<version>`"
- "DL3033 warning: Specify version with `yum install -y <package>-<version>`"
- "DL3048 style: Invalid label key"
- "DL3003 warning: Use WORKDIR to switch to a directory"
- "DL3018 warning: Pin versions in apk add. Instead of apk add <package> use apk add <package>=<version>"
- "DL3037 warning: Specify version with zypper install -y <package>[=]<version>"
Fixes#3107
Signed-off-by: Wainer dos Santos Moschetta <wainersm@redhat.com>