chore: switch database engine to sqlite (fixes #9954) (#9965)

Switch the database from LevelDB to SQLite, for greater stability and
simpler code.

Co-authored-by: Tommy van der Vorst <tommy@pixelspark.nl>
Co-authored-by: bt90 <btom1990@googlemail.com>

lib/protocol/protocol_test.go

@@ -10,10 +10,8 @@ import (
 	"bytes"
 	"context"
 	"encoding/hex"
-	"encoding/json"
 	"errors"
 	"io"
-	"os"
 	"sync"
 	"testing"
 	"time"
@@ -280,28 +278,6 @@ func TestUnmarshalFDPUv16v17(t *testing.T) {
 	}
 }
 
-func testMarshal(t *testing.T, prefix string, m1, m2 proto.Message) bool {
-	buf, err := proto.Marshal(m1)
-	if err != nil {
-		t.Fatal(err)
-	}
-
-	err = proto.Unmarshal(buf, m2)
-	if err != nil {
-		t.Fatal(err)
-	}
-
-	bs1, _ := json.MarshalIndent(m1, "", "  ")
-	bs2, _ := json.MarshalIndent(m2, "", "  ")
-	if !bytes.Equal(bs1, bs2) {
-		os.WriteFile(prefix+"-1.txt", bs1, 0o644)
-		os.WriteFile(prefix+"-2.txt", bs2, 0o644)
-		return false
-	}
-
-	return true
-}
-
 func TestWriteCompressed(t *testing.T) {
 	for _, random := range []bool{false, true} {
 		buf := new(bytes.Buffer)