GeezerVison

…ipt cmdlets (PowerShell#4709)

When dotting a script cmdlet, the locals of automatic variables from the `PSScriptCmdlet` is not set up in the current scope before parameter binding. The fix is to push the locals in `CommandProcessor.OnSetCurrentScope` and pop them in `CommandProcessor.OnRestorePreviousScope`, which will be called from `SetCurrentScopeToExecutionScope` and `RestorePreviousScope` respectively.

Summary of changes:
1. When a new local scope is used, currently we set the locals for `CommandProcessor` right before parameter binding (in `BindCommandLineParametersNoValidation`); we set the locals for `ScriptCommandProcessor` in `Prepare`. I moved both to the constructor, right after the new scope is created so that the code is more consistent.

2. In `CmdletParameterBinderController.cs`, we set up the `PSBoundParameters` and `MyInvocation` variables in `HandleCommandLineDynamicParameters` again, which I think is unnecessary because this method is only called from `BindCommandLineParametersNoValidation`, where the setup is done for the first time.

3. Currently, the locals will be set for dotted script cmdlet in `EnterScope()` and `ExitScope()`. Now, that logic is moved to `OnSetCurrentScope` and `OnRestorePreviousScope` of `CommandProcessor`. This not only makes sure that locals are set before parameter binding, but also is consistent with the `ScriptCommandProcessor`.