Inconsistent display of parameter information depending on notation

[Namenloser-Held]

Describe the bug
The way parameter information is displayed is inconsistent across different scenarios, when using the object-oriented notation.

To Reproduce

1. For a function declaration with a self argument, type ':' on an object. The auto-completion documentation shows the function declaration with the self argument.
   
2. The self argument is shown on hover, but not in the parameter information (CTRL+SHIFT+SPACE).
   
3. For a method declaration, type '.' on the table name. The auto-completion documentation shows the method declaration without the self argument.
   
4. Complete the function call. A hover over the method name shows the method declaration without the self argument.
   

Expected behavior
The parameter information is presented in a consistent way.

The way the parameter information is presented depends on the used notation
e.g. someObject:reset -> someObject:reset(param2: Test)
e.g. someObject.store -> someObject.store(self: Test2, param2: Test)

Environment (please complete the following information):

• OS: Windows 10
• Client: VSCode
• VSCode version: 1.56.2
• Extension version: 1.21.1

[sumneko]

Hover always shows the form of the function definition.
This design is considered to resolve some ambiguities, such as ('xxx'):format(xx) --> string.format

[sumneko]

If you have any other suggests, you are free to reopen this issue