code_review: PR #386

* rename `FirstParentFilterToggled` to `EnableFirstParentInHistories`
* remove `FirstParentFilterEnabled` from repo settings - it should not been saved
* move toggle button from repository toolbar to histories switcher
* tooltip translations
* new icon for `Icons.FirstParentFilter`
* extends commit graph to support `--first-parent` option

src/Models/RepositorySettings.cs

@@ -70,12 +70,6 @@ namespace SourceGit.Models
             set;
         } = false;
 
-        public bool FirstParentFilterEnabled
-        {
-            get;
-            set;
-        } = false;
-
         public AvaloniaList<string> Filters
         {
             get;