WI #2190 Handle Picture Character String replacement as Partial Cobol Word replacement

[fm-117]

Fixes #2190.

Another hack in the REPLACE mechanism to handle simple case of PIC replacements which are now considered at text level instead of token level.

Note that the preprocessor test PgmCopyReplacing is now wrong on its last part. This is because the test was previously based on 2 bugs (#2078 and #2190). With this current fix, we now observe effects of #2078 and also the fact that in a multiple replace instruction the parser should not attempt to replace the same token twice (see #2212).