Consider adding resolution command buttons to diff shown when import detects a server-side change

[gjsjohnmurray]

Since PR #200 a server-side change produces this dialog during import of the local version:

Clicking "Compare" gives this:

Unlike the equivalent diff which appears if the local file is modified outside VS Code before being saved (and which also appears when the scenario arises for an isfs-type workspace root), the one shown above lacks command buttons to resolve the conflict.

Here is that other story:

Click "Compare":