SampleAugmentation field list

Description

If a field with a string type is given in the list of excluded fields an error occurs.

Steps to reproduce

otbcli_SampleAugmentation -in Samples_region_1_seed0_learn.sqlite -field code -label 12 -samples 10 -exclude region code originfid tile_o -out Samples_region_1_seed0_learn_augmented.sqlite

(FATAL): itk::ERROR: ListViewParameter(0x12d6320): Value region not found in the list of choices: code, originfid, sentinel2_b2_20151230,...

But the field "region" exists.

In the application's code, only field with of integer or float type are consider -> otbSampleAugmentation.cxx, line 176 (which is consistent with the application purpose).

Adding fields with string type to the exclude field list could improve the use of the application, users could provide all field list without beforehand checking their type.