[drbd] Split legacy and patched DRBD stacks

[IvanOgurchenok]

Description

This PR separates the DRBD stack used by the legacy LINSTOR control plane from the stack used by the new control plane.

The legacy LINSTOR path now uses vanilla DRBD 9.2.18 and drbd-utils 9.30.0. The new control-plane path continues to use the flant-patched DRBD 9.2.18 and drbd-utils 9.32.0 stack.

The DRBD install NodeGroupConfiguration also selects the desired DRBD version and module image according to internal.newControlPlane, and handles empty, non-DRBD-9, or malformed loaded versions without failing the bashible run.

The final drbdReactor and drbdReactorLegacy images now remove /opt/svace, which is build-only static analysis tooling inherited from the builder base and is not needed at runtime.

Why do we need it, and what problem does it solve?

The legacy LINSTOR control plane is more sensitive to newer drbd-utils behavior and should stay on the vanilla DRBD userspace/kernel pair. At the same time, the new control plane requires the flant-patched DRBD stack.

Keeping these paths separate avoids mixing incompatible kernel/userspace ABI variants and reduces the risk of breaking legacy LINSTOR while still allowing the new control plane to use patched DRBD features.

The bashible version-check fix prevents DRBD installation from failing when /proc/drbd contains an empty, old, or malformed loaded module version.

Removing /opt/svace keeps unnecessary build tooling out of the final reactor runtime filesystem. The image still inherits the same builder base, so this is a conservative cleanup rather than a full image-layer optimization.

What is the expected result?

When internal.newControlPlane is false, the module should render and install the legacy DRBD stack:

• drbdLegacy image for DRBD kernel module installation;
• drbdReactorLegacy image for the legacy LINSTOR node sidecar;
• vanilla DRBD 9.2.18 and drbd-utils 9.30.0.

When internal.newControlPlane is true, the module should continue to render and install the patched DRBD stack:

• drbd image for DRBD kernel module installation;
• drbdReactor image for the new control-plane sidecar;
• flant-patched DRBD 9.2.18 and drbd-utils 9.32.0.

If the currently loaded DRBD version is empty, not a DRBD 9.x semver, or lower than the desired version, bashible should request a rebuild/reboot path instead of failing on d8-semver compare.

The final drbdReactor and drbdReactorLegacy runtime filesystems should not contain /opt/svace.

Checklist

• The code is covered by unit tests.
• e2e tests passed.
• Documentation updated according to the changes.
• Changes were tested in the Kubernetes cluster manually.