Invalidate GeoPackage cache by tile download timestamp

[ComBatVision]

Add special logic to TiledSurfaceImage and AbstractTiledElevationCoverage, which should check if cached version of tile was outdated (downloaded and saved to cache long time ago) and force retrieval of this tile from online source to refresh cache.

To implement this feature GeoPackage tiles table should be extended with timestamp describing the tile retrieval time.

This timestamp should be analyzed during retrieval process and if it is too old, online tile should be requested together with cached tile result.