NoPartialFunctions: stop suggesting tryLast instead of tail

tryLast doesn't have the same goal as tail; let's rather suggest
FSharpx.Collections.Seq.tryHeadTail extension for now, which has
just been merged [1] and will be in 3.0.0 release (at least until
we have a tryTail of some sort [2]).

[1] fsprojects/FSharpx.Collections#176
[2] fsharp/fslang-suggestions#803

src/FSharpLint.Core/Rules/Conventions/NoPartialFunctions.fs

@@ -35,7 +35,7 @@ let private partialFunctionIdentifiers =
         ("Array.findBack", Function "Array.tryFindBack")
         ("Array.head", Function "Array.tryHead")
         ("Array.last", Function "Array.tryLast")
-        ("Array.tail", Function "Array.tryLast")
+        ("Array.tail", Function "FSharpx.Collections.Seq.tryHeadTail")
         ("Array.reduce", Function "Array.fold")
         ("Array.reduceBack", Function "Array.foldBack")
         ("Array.pick", Function "Array.tryPick")
@@ -48,7 +48,7 @@ let private partialFunctionIdentifiers =
         ("Seq.findBack", Function "Seq.tryFindBack")
         ("Seq.head", Function "Seq.tryHead")
         ("Seq.last", Function "Seq.tryLast")
-        ("Seq.tail", Function "Seq.tryLast")
+        ("Seq.tail", Function "FSharpx.Collections.Seq.tryHeadTail")
         ("Seq.reduce", Function "Seq.fold")
         ("Seq.reduceBack", Function "Seq.foldBack")
         ("Seq.pick", Function "Seq.tryPick")
@@ -61,7 +61,7 @@ let private partialFunctionIdentifiers =
         ("List.findBack", Function "List.tryFindBack")
         ("List.head", Function "List.tryHead")
         ("List.last", Function "List.tryLast")
-        ("List.tail", Function "List.tryLast")
+        ("List.tail", Function "FSharpx.Collections.Seq.tryHeadTail")
         ("List.reduce", Function "List.fold")
         ("List.reduceBack", Function "List.foldBack")
         ("List.pick", Function "List.tryPick")