test(apache-httpd-status): rewrite fixtures, use Red Hat stack, modernize run

Rename the opaque EXAMPLE01..08 fixtures to
`<os>-httpd-<version>-<mpm>-ext-<on|off>[-<n>]` so the intent of each
scenario is obvious at a glance, and replace the CentOS 8 captures with
fresh RHEL 8 / 9 / 10 (httpd 2.4.37 / 2.4.62 / 2.4.63) captures taken
from `registry.access.redhat.com/ubi{8,9,10}/ubi` containers. Each
ExtendedStatus-On scenario carries the full three-call sequence that
the plugin needs to progress through "Waiting for more data (1)" and
"(3)" to its real output.

Rewrite the `run` file from per-method `shell_exec` calls to the
declarative SCENARIOS / `lib.lftest.run()` pattern the other plugins
use, with a cache-DB reset between scenarios so they do not bleed into
each other. Assertions are regex-based so re-captures do not have to
match specific worker counts or byte totals.

The old Fedora 34 captures are kept for their MPM coverage: one event
MPM scenario, one worker MPM scenario (which does not emit ConnsTotal
/ ConnsAsync* and exercises the "field is missing" branches), and one
worker MPM scenario that additionally lacks CPULoad.

Author: markuslf