[UDP] IAP Product fields are not validated for length and large amounts of data will crash UDP Server

After installing the Universal Distribution Portal (UDP) package, "UDP Settings" will be exposed to the user, where the user can add IAP Products. Currently, none if the IAP Product fields are validated for length. If the user submitted a large amount of data (for example 10 million characters), there is no validation preventing this and the Push will throw an error and the UDP Server/instance managing that project will then crash until it is cycled back up after an extended duration (this can be confirmed by trying to Pull, or trying to access the project through the UDP web console).

Steps to reproduce:
- In Unity 2019.3, create a new project and install the Universal Distribution Portal (UDP) package (alternatively download the attached project)
- Menu: Window > Universal Distribution Portal > Settings
-Inspector (UDP Settings) > Register the project with Unity Cloud Services if the UDP Settings Inspector pane indicates it is not already
- Inspector (UDP Settings) > IAP Catalog > Add new IAP
- Configure the new IAP Product with any information, but in one of the fields, placing a very large text value (10 million characters for example)
- "Push" the IAP Product
- Observe "cause: Internal Server Error" error is thrown
- "Pull" to pull from the UDP server
- Observe the same error as previous is thrown
- Click "Go to UDP console" > Access the project being worked on
- Observe the UDP Server / instance managing this project has crashed and is inaccessible, showing an "Internal Server Error"