[c++] PlatformConfig tile/cell order and filter options should be case insensitive

[nguyenv]

Currently the C++ PlatformConfig only handles options as put forth by the SOMA Python API. Some of the options in the SOMA R API differ slightly and need to be added in C++.

• Tile/cell order and filter options should be case insensitive
• Add all name to filter mappings (ie. "rle" and "rlefilter" should both map to tiledb::Filter::RleFilter)
• Handle global and unordered ordering

Relates to #2471