Add support to specify parameter multiple times

[thschmitt]

• Remove complicated array indexing for root arguments
• Add support to specify parameter multiple times to create object array structure

e.g.

uipath app create --users "name=Administrator" --users "name=Guest"

will create the following JSON:

{
  "users": [
    { "name": "Guest" },
    { "name": "Administrator" }
  ]
}