[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/tetratelabs/wazero/internal/u64/u64.go

@@ -0,0 +1,15 @@
+package u64
+
+// LeBytes returns a byte slice corresponding to the 8 bytes in the uint64 in little-endian byte order.
+func LeBytes(v uint64) []byte {
+	return []byte{
+		byte(v),
+		byte(v >> 8),
+		byte(v >> 16),
+		byte(v >> 24),
+		byte(v >> 32),
+		byte(v >> 40),
+		byte(v >> 48),
+		byte(v >> 56),
+	}
+}