[experiment] add alternative wasm sqlite3 implementation available via build-tag (#2863)

This allows for building GoToSocial with [SQLite transpiled to WASM](https://github.com/ncruces/go-sqlite3) and accessed through [Wazero](https://wazero.io/).

vendor/github.com/ncruces/go-sqlite3/internal/util/json.go

@@ -0,0 +1,35 @@
+package util
+
+import (
+	"encoding/json"
+	"strconv"
+	"time"
+	"unsafe"
+)
+
+type JSON struct{ Value any }
+
+func (j JSON) Scan(value any) error {
+	var buf []byte
+
+	switch v := value.(type) {
+	case []byte:
+		buf = v
+	case string:
+		buf = unsafe.Slice(unsafe.StringData(v), len(v))
+	case int64:
+		buf = strconv.AppendInt(nil, v, 10)
+	case float64:
+		buf = strconv.AppendFloat(nil, v, 'g', -1, 64)
+	case time.Time:
+		buf = append(buf, '"')
+		buf = v.AppendFormat(buf, time.RFC3339Nano)
+		buf = append(buf, '"')
+	case nil:
+		buf = append(buf, "null"...)
+	default:
+		panic(AssertErr())
+	}
+
+	return json.Unmarshal(buf, j.Value)
+}