Refactor kernel support

- Remove kernel imports and kmods images
- Repurpose KernelOverride as container path
- Support Kernel.Version as version prefix for kernel selection
- Compare initramfs by version

Signed-off-by: Jonathon Anderson <janderson@ciq.com>

internal/pkg/util/version.go

@@ -0,0 +1,26 @@
+package util
+
+import (
+	"regexp"
+	"strings"
+
+	"github.com/hashicorp/go-version"
+)
+
+var (
+	versionPattern *regexp.Regexp
+)
+
+func init() {
+	versionPattern = regexp.MustCompile(`\d+\.\d+\.\d+(-[\d\.]+|)`)
+}
+
+func ParseVersion(versionString string) *version.Version {
+	matches := versionPattern.FindAllString(versionString, -1)
+	for i := len(matches) - 1; i >= 0; i-- {
+		if version_, err := version.NewVersion(strings.TrimSuffix(matches[i], ".")); err == nil {
+			return version_
+		}
+	}
+	return nil
+}