HPCC-9927 Logical File Details Issues

Sprayed file displays confusing messages for ECL/DEF and XML.
Sprayed file does not show content.
Desprayed file does not show content.

Fixes HPCC-9927

Signed-off-by: Gordon Smith <gordon.smith@lexisnexis.com>
Merge pull request #4784 from GordonSmith/HPCC-9927

HPCC-9927 Logical File Details Issues

Reviewed-By: Miguel Vazquez <miguel.vazquez@lexisnexis.com>
Reviewed-By: Richard Chapman <rchapman@hpccsystems.com>