Make it more robust to read string from table workspace. Refs #6863.

String in table workspace may have unexpected extra spaces if the
workspace is loaded from Nexus file.  Enable the algorithm to trim the
while spaces such that the parameter names read from workspace can match
to those defined in peak functions.
Cleaned the code.  Refs #6863.
Enable to trim spaces in parameter name.  Refs #6863.
Merge branch 'feature/6863_refactor_lebailfit' into develop