Switch to better document selecting

[TylerLeonhardt]

Trying to get the vim extension working, I noticed that the filetype for PowerShell files was ps1 instead of powershell.

This adds ps1 and a few others to our document selector.

I really should get the vim extension using powershell but it's harder than it sounds because any vim plugin can change this.

[TylerLeonhardt]

Here is an overview of what got changed by this pull request:

Issues
======
+ Solved 7
           

Complexity increasing per file
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- src/PowerShellEditorServices/Utility/LspUtils.cs  1
         

Clones added
============
- src/PowerShellEditorServices/Services/TextDocument/Handlers/SignatureHelpHandler.cs  5
- src/PowerShellEditorServices/Services/TextDocument/Handlers/DocumentSymbolHandler.cs  2
- src/PowerShellEditorServices/Services/TextDocument/Handlers/CompletionHandler.cs  2
- src/PowerShellEditorServices/Services/TextDocument/Handlers/HoverHandler.cs  5
- src/PowerShellEditorServices/Services/TextDocument/Handlers/FormattingHandlers.cs  1
- src/PowerShellEditorServices/Services/TextDocument/Handlers/FoldingRangeHandler.cs  3
- src/PowerShellEditorServices/Services/TextDocument/Handlers/DocumentHighlightHandler.cs  1
- src/PowerShellEditorServices/Services/TextDocument/Handlers/DefinitionHandler.cs  2
         

See the complete overview on Codacy