Added targets for RHEL 5 and for 4 Ubuntu LTS releases, new rules for CentOS 5, RHEL 6 and RHEL 7

[hkortti]

This pull request adds new targets and rules:

• New target for RHEL 5 with rule for "Apache/2.2.3 (Red Hat)" as per https://ftp.redhat.com/pub/redhat/linux/enterprise/5Server/en/os/SRPMS/
• New rule for CentOS 5 for "Apache/2.2.3 (CentOS)" as per https://ftp.iij.ad.jp/pub/linux/centos-vault/5.11/updates/x86_64/RPMS/
• New targets for Ubuntu LTS releases Trusty Tahr (already EOL), Xenial Xerus (unless ESM), Bionic Beaver (unless ESM), and Focal Fossy (EOL upcoming 2025-05-31, unless ESM). Apache versions for each distro release verified from https://launchpad.net/ubuntu/+source/apache2/+publishinghistory . EOL dates verified from https://endoflife.date/ubuntu and https://wiki.ubuntu.com/Releases .
• New longer Apache rule for RHEL 6: "Apache/2.2.15 (Red Hat Enterprise Linux)" as the longer distro name appears in some Shodan results. Previously in RHEL 5 and earlier only "(Red Hat)" was used, and it was changed to "(Red Hat Enterprise Linux)" some time during the RHEL 6 release lifecycle.
• New shorter Apache rule for RHEL 7: "Apache/2.4.6 (Red Hat)" as the shorter distro name appears in some Shodan results and therefore increases coverage for true positives.