Refactor same_arg_param and repeat_param

[bugy]

At the moment these 2 settings have reverse meaning, this should be fixed

[bugy]

Fixed. I did the following changes:

• same_arg_param: now "removes a whitespace" between param and value (e.g. -flag=value)
• repeat_param: removed, in favor of new multiselect_argument_type
• multiple_arguments: removed, in favor of new multiselect_argument_type
• multiselect_argument_type: NEW. Can be used for multiselect only. The value should be one of:
  • single_argument (default): sends all the values as a single argument, separated by separator (-param value1,value2,value3)
  • argument_per_value: sends every value as a separate argument (-param value1 value2 value3)
  • repeat_param_value: sends every value as a separate argument and repeat param for each value (-param value1 -param value2 -param value3)

These changes should be applied automatically to existing configs via a migration (run on server startup)

@miksir FYI. Hopefully I won't break anything for your setup