Added missing test file. Substituted the obsolete xmlSchemaValidError(s)

* test/schemas/import-bad-1_0.imp: Added missing test file.
* xmlschemas.c include/libxml/xmlerror.h include/libxml/xmlschemas.h:
  Substituted the obsolete xmlSchemaValidError(s) for xmlParserErrors
  - see #150840.
  Changed the import of schemas to allow failure of location
  of a resource to be imported.
* result/schemas/all_* result/schemas/any3_0_0.err
  result/schemas/choice_* result/schemas/import1_0_0.err
  result/schemas/list0_0_1.err result/schemas/list0_1_0.err
  result/schemas/list0_1_1.err result/schemas/ns0_0_2.err
  result/schemas/ns0_1_2.err: Adapted regression test results.
33 files changed