Provide diagnostic marker API in $psEditor

It would be useful if there was an API to add diagnostic markers to script files so that any editor command could add "squigglies" to arbitrary regions of an open file. Markers would be added in relation to a named "layer" which would allow Editor Services to keep track of a unique set of markers for each module or use case.

The API might look something like this:

$file = $context.CurrentFile
# OR: $file = $psEditor.Workspace.GetFile("filePath.ext")
$file.SetMarkers("MarkerLayerName", markerArray)

We should also provide an API for clearing markers, either for a specific layer or for all layers:

$file.ClearMarkers("MarkerLayerName")
$file.ClearMarkers()

Once this API exists, I'll use it to implement the new integration model for PSScriptAnalyzer in issue #213.

FEEDBACK NEEDED: Is SetMarkers good enough or should it be SetFileMarkers, SetDiagnosticMarkers or something else?

Commencez par examiner l’API de fichiers existante de $psEditor et l’issue #213 afin de comprendre comment les marqueurs de diagnostic seraient consommés. Déterminez la conception de la couche de marqueurs et de la nomenclature, puis définissez le comportement de SetMarkers et ClearMarkers pour des régions de fichier arbitraires et pour chaque couche.