Throw error on invalid workspace names

[peterfpeterson]

The ADS exposes several methods where the names of workspaces become python variable names and is described in the user documentation. The general rules are (taken from)

• Names are case-sensitive
• Names cannot start with a digit
• Names can contain letters, numbers, and underscores

AnalysisDataService::rename() does not currently call AnalysisDataService::verifyName() which needs to be changed. All of the additional checks can be put into AnalysisDataService::isValid() which is called by AnalysisDataService::verifyName().

Note that unicode characters are allowed, but they may not be appropriate for workspace names because the ADS stores the names as std::string.