Update deprecated GIBS API parameters, e.g. TileMatrixSet values

[rboller]

Across many/most/all of the GIBS Web Examples, there are uses of deprecated GIBS TileMatrixSet values and possibly others. E.g. in this Leaflet example, the TileMatrxSet value is EPSG4326_250m but now the appropriate value has been simplified to 250m.

So this repo should be scrubbed for any instances of this and any similarly deprecated values. Current values can be found in the GIBS GetCapabilities documents.

[rboller]

@mcechini are you aware of any other parameters beyond TileMatrixSet that needs to be updated in these examples?

[mcechini]

I took a quick pass through most of the examples and I don't see anything else that needs to be changed.