Add allowSave parameter to GenerateTokenRequest SDK API call

In current GenerateTokenRequest method of SDK API, there is a boolean parameter called "allowSaveAs". That's good, but we really need another one for "allowSave". The reason both are important, in addition to the "Edit" access method, is to support the Use Case where we have a set of reports that we don't want the customer to change. These are reports we've created and they shouldn't be altered by anyone but us (when we deploy from PBI Desktop). However, we DO want users to have the ability to do their own customizing of our reports. For this scenario, we would need "allowSave" to be FALSE, and "allowSaveAs" to be TRUE. This is also needed due to the fact that MS doesn't allow us to set permissions at the report level within a workspace. Thank you.