Added support for Badger as an alternative storage backend

internal/datastore/badger_datastore/badger_datastore.go

@@ -0,0 +1,36 @@
+package badgerdatastore
+
+import (
+	"encoding/gob"
+
+	"github.com/dgraph-io/badger/v4"
+	"github.com/pikami/cosmium/internal/logger"
+)
+
+type BadgerDataStore struct {
+	db *badger.DB
+}
+
+func NewBadgerDataStore() *BadgerDataStore {
+	gob.Register([]interface{}{})
+
+	badgerOpts := badger.DefaultOptions("").WithInMemory(true)
+
+	db, err := badger.Open(badgerOpts)
+	if err != nil {
+		panic(err)
+	}
+
+	return &BadgerDataStore{
+		db: db,
+	}
+}
+
+func (r *BadgerDataStore) Close() {
+	r.db.Close()
+}
+
+func (r *BadgerDataStore) DumpToJson() (string, error) {
+	logger.ErrorLn("Badger datastore does not support state export currently.")
+	return "{}", nil
+}