Duplicate schedule name with import from CSV makes pyrevit error

[DuncanLithgow]

Describe the bug
Trying to import a csv as a wall key schedule because the first try looks all wrong

To Reproduce
Import the same csv to the same category twice

Expected behavior
pyRevit should create a new schedule with an iteration in the name. For example

• ScheduleFromCVS
• ScheduleFromCSV(2)

Desktop (please complete the following information):

• OS: Win10
• pyRevit Version pyRevit 4.7.6:277:2020.2
• pyRevit Environment: Open a command prompt and run the command below. Replace these lines with the results. Take a look at this markdown guide and wrap the command results in ``` when pasting here for correct formatting.

(c) 2018 Microsoft Corporation. All rights reserved.

```C:\Users\xxx>pyrevit env
==> Registered Clones (full git repos)
==> Registered Clones (deployed from archive/image)
master | Deploy: "basepublic" | Branch: "master" | Version: "4.7.6" | Path: "C:\Users\dli\AppData\Roaming\pyRevit-Master"
==> Attachments
master | Product: "Autodesk Revit 2020" | Engine: 277 | Path: "C:\Users\dli\AppData\Roaming\pyRevit-Master" | Manifest: "C:\Users\dli\AppData\Roaming\Autodesk\Revit\Addins\2020\pyRevit.addin"
master | Product: "2019.2.2 Hotfix" | Engine: 277 | Path: "C:\Users\dli\AppData\Roaming\pyRevit-Master" | Manifest: "C:\Users\dli\AppData\Roaming\Autodesk\Revit\Addins\2019\pyRevit.addin"
master | Product: "2018.3.3 Security Fix" | Engine: 277 | Path: "C:\Users\dli\AppData\Roaming\pyRevit-Master" | Manifest: "C:\Users\dli\AppData\Roaming\Autodesk\Revit\Addins\2018\pyRevit.addin"
master | Product: "2017.2.5 Security Fix" | Engine: 277 | Path: "C:\Users\dli\AppData\Roaming\pyRevit-Master" | Manifest: "C:\Users\dli\AppData\Roaming\Autodesk\Revit\Addins\2017\pyRevit.addin"
==> Installed Extensions
==> Default Extension Search Path
C:\Users\dli\AppData\Roaming\pyRevit\Extensions
==> Extension Search Paths
==> Extension Sources - Default
https://github.com/eirannejad/pyRevit/raw/master/extensions/extensions.json
==> Extension Sources - Additional
==> Installed Revits
Autodesk Revit 2021 | Version: 21.1.0.108 | Build: 20200708_1515(x64) | Language: 1033 | Path: "C:\Program Files\Autodesk\Revit 2021"
Autodesk Revit 2020 | Version: 20.2.20.31 | Build: 20200426_1515(x64) | Language: 1033 | Path: "C:\Program Files\Autodesk\Revit 2020"
2019.2.2 Hotfix | Version: 19.2.20.24 | Build: 20190808_0900(x64) | Language: 1033 | Path: "C:\Program Files\Autodesk\Revit 2019"
2018.3.3 Security Fix | Version: 18.3.3.18 | Build: 20190510_1515(x64) | Language: 1033 | Path: "C:\Program Files\Autodesk\Revit 2018"
2017.2.5 Security Fix | Version: 17.0.1169.0 | Build: 20190508_0315(x64) | Language: 1033 | Path: "C:\Program Files\Autodesk\Revit 2017"
==> Running Revit Instances
Error: Object reference not set to an instance of an object.
Run with "--debug" option to see debug messages```

**Additional context**
Here's the console text

```ERROR [pyrevit.revit.db.transaction] Error in Transaction Context. Rolling back changes. | <type 'exceptions.Exception'>:Name must be unique. 
Parameter name: name

IronPython Traceback:
Traceback (most recent call last):
 File "C:\Users\dli\AppData\Roaming\pyRevit-Master\extensions\pyRevitTools.extension\pyRevit.tab\Drawing Set.panel\views.stack\Schedules.pulldown\Create Schedule from CSV.pushbutton\script.py", line 160, in <module>
 File "C:\Users\dli\AppData\Roaming\pyRevit-Master\extensions\pyRevitTools.extension\pyRevit.tab\Drawing Set.panel\views.stack\Schedules.pulldown\Create Schedule from CSV.pushbutton\script.py", line 36, in create_key_schedule
Exception: Name must be unique.
Parameter name: name

Script Executor Traceback:
Autodesk.Revit.Exceptions.ArgumentException: Name must be unique.
Parameter name: name
 at Microsoft.Scripting.Interpreter.ThrowInstruction.Run(InterpretedFrame frame)
 at Microsoft.Scripting.Interpreter.Interpreter.HandleException(InterpretedFrame frame, Exception exception)
 at Microsoft.Scripting.Interpreter.Interpreter.Run(InterpretedFrame frame)
 at Microsoft.Scripting.Interpreter.LightLambda.Run2[T0,T1,TRet](T0 arg0, T1 arg1)
 at IronPython.Compiler.PythonScriptCode.RunWorker(CodeContext ctx)
 at PyRevitLabs.PyRevit.Runtime.IronPythonEngine.Execute(ScriptRuntime& runtime)```

[eirannejad]

Fixed and will be published with next release

[DuncanLithgow]

of course the schedule might already be on a sheet, so even better would be if it asks whether it should overwrite or create a new schedule.

[eirannejad]

So the tool creates Key schedules. You can't have two key schedules feeding values to the same parameters. Only one can exist

[DuncanLithgow]

Okay, sure. But is there is no way to replace the previous data with new data in the same schedule?

[eirannejad]

Great question. I need to look at the api. I just understood what your problem is. You have a schedule on a sheet that you don't want to delete every time there is new data. Got it! Sorry I'm a bit all over the place these days working on so many different things.

[eirannejad]

• Okay the API supports removing rows in key schedules. I'll implement that and will rework the schedule conflict resolution logic

[DuncanLithgow]

Brilliant! I look forward to seeing it sometime when someone submits a patch.

[eirannejad]

Fixed and will be published with next release