[#41] Delete codan markers

[ghentschke]

prior to open a file with the LSP based C/C++ editor. When a C/C++ file has been opened prior by the old CDT C/C++ editor the codan markers are persistent and must be removed from the resource.

fixed #41

[jonahgraham]

I think this is an interesting and simple approach. I guess the longer term solution will be to having some preference / setting that disables codan (and CDT parser) when lsp is in use, and when that setting is enabled all the codan errors are removed.

[ghentschke]

@jonahgraham Thank you!

[ruspl-afed]

I think this is an interesting and simple approach

Yes, if it will delete markers inside WorkspaceJob and not in UI thread.

[jonahgraham]

@ghentschke, I think @ruspl-afed makes a good point, it may be better to do the work asynchronously. I'm not sure if needs a full workspace job as that locks whole workspace, deleteMarkers will only lock on the resource being modified.

[ghentschke]

@ruspl-afed and @jonahgraham Your are right. I'll provide a PR for that.

[ruspl-afed]

I'm not sure if needs a full workspace job as that locks whole workspace

We don't need to lock the whole workspace, locking corresponding IResource looks enough here

[ruspl-afed]

And this is the second time when we do modifications from "isEnabled" method, we need to improve this as well