Fix multiple string replacement when using TextEdit

[danielkrusegit]

This pull-request is related the following issue: #152

Issue
The implementation of a completion is working fine when using the CompletionContributor to modify the document but when an InsertHandler is added to the LookupElement using a TextEdit, the affected text is replaced twice.

The CompletionContributor replaces the text in the range to an empty LookUpString. Afterwards, the InsertHandler is called, which replaces the affected Range again, which is no longer present.

Example

The completion starts with
hello : Intege; //Test
The CompletionContributor replaces Intege to blank
hello : ; //Test
The InsertHandler replaces the range of the Intege that is now ; //Te to Integer64
hello : Integer64st

Server response:

[
  left = null
  right = CompletionList [
  isIncomplete = false
    items = ArrayList (
      CompletionItem [
        label = "Integer64"
        textEdit = TextEdit [
          range = Range [
            start = Position [
              line = 1
              character = 10
            ]
            end = Position [
              line = 1
              character = 16
            ]
          ]
          newText = "Integer64"
        ]
        kind = Interface
        sortText = "2)Integer64"
        commitCharacters = ArrayList (
          "."
        )
        data = {}
        detail = null
        documentation = null
        deprecated = null
        preselect = null
        filterText = null
        insertText = null
        insertTextFormat = null
        additionalTextEdits = null
        command = null
      ]
    )
  ]
] 

Solution
I solved the issue by skipping the first step. The CompletionContributor replaces now from Intege to Intege (No changes in the document). Maybe there is a better solution to solve this issue.