URIs should be decoded before reading from .3dtiles

[lilleyse]

E.g. example%20file.gltf should be decoded to example file.gltf before reading from a .3dtiles database.

CC CesiumGS/3d-tiles#727 (comment)

[javagl]

@lilleyse I think that this will mainly affect the PackageServer (and may therefore be addressed in #86 ). It could raise some subtle questions when we try to add encoding/decoding logic in the layer that accesses the database file. (For 3TZ, there is a "minor" normalization step at

3d-tiles-tools/src/tilesets/packages/ArchiveFunctions3tz.ts

Line 301 in 49d9b29

private static normalizePath(path: string) {

, but that's unrelated to encoding/decoding).

When someone does
const value = tilesetSource.getValue("example%20file.gltf");
then this should return the file if and only if it is really stored under that name in the package. (We still have to add some clarifications/constraints to the spec document, though...)