gdal_rasterize: issue with -burn (master)

[rouault]

@elpaso There are regressions compared to 3.9

The following command lines no longer work:

1. Source filename directly after -burn

$ rm -f out.tif; gdal_rasterize -ts 10 10 -burn 1 autotest/ogr/data/poly.shp out.tif
ERROR 1: Failed to parse 'autotest/ogr/data/poly.shp' as number: pattern 'autotest/ogr/data/poly.shp' does not match to the end

but adding -l poly after -burn works:

$ rm -f out.tif; gdal_rasterize -ts 10 10 -burn 1 -l poly autotest/ogr/data/poly.shp out.tif
0...10...20...30...40...50...60...70...80...90...100 - done.

2. Or (probably same underlying issue):

$ rm -f out.tif; gdal_rasterize -ts 10 10 autotest/ogr/data/poly.shp out.tif -burn 1
ERROR 1: Failed to parse 'autotest/ogr/data/poly.shp' as number: pattern 'autotest/ogr/data/poly.shp' does not match to the end

3. The non documented -burn "val1 val2 ..." no longer works:

$ rm -f out.tif; gdal_rasterize -ts 10 10 -burn "1 2" -l poly autotest/ogr/data/poly.shp out.tif
ERROR 1: Failed to parse '1 2' as number: pattern '1 2' does not match to the end

That point is minor compared to 1) and 2). I believe we have addressed that for some arguments of other utilities, but maybe I'm wrong / can't remember which ones