More reliable exception handling in Control.App

Convert `App.Control.Exception` interface to an alias to `HasErr`.

Probably `Exception` interface need to be deprecated or removed.

Note similar problem exists with `PrimIO` calling `PrimIO, Exception`,
also need to be fixed.

Fix this scenario:

```
throwBoth : Has [Exception String, Exception Int] es => App es ()

throwOne : Has [Exception Int] es => App es Int
throwOne {es} = handle {err = String} {e = es} throwBoth (\r => pure 1) (\e => pure 3)
```

With this commit it works, before this commit it failed with:

```
Error: While processing right hand side of throwOne. Can't find an implementation for Exception Int (String :: es).

TestException.idr:8:48--8:57
   |
 8 | throwOne {es} = handle {err = String} {e = es} throwBoth (\r => pure 1) (\e => pure 3)
   |                                                ^^^^^^^^^
```

libs/base/Control/App.idr

@@ -263,17 +263,10 @@ new val prog
                 MkApp res = prog @{st} in
                 res
 
+||| An alias for `HasErr`.
 public export
-interface Exception err e where
-  ||| Throw an exception.
-  ||| @ ev Value of the exception.
-  throw : (ev : err) -> App e a
-  ||| Use with a given computation to do exception-catching.
-  ||| If any exception is raised then the handler is executed.
-  ||| @ act The computation to run.
-  ||| @ k   Handler to invoke if an exception is raised.
-  ||| @ ev  Value of the exception passed as an argument to the handler.
-  catch : (act : App e a) -> (k : (ev : err) -> App e a) -> App e a
+Exception : Error -> List Error -> Type
+Exception = HasErr
 
 findException : HasErr e es -> e -> OneOf es MayThrow
 findException Here err = First err
@@ -284,10 +277,11 @@ findError Here (First err) = Just err
 findError (There p) (Later q) = findError p q
 findError _ _ = Nothing
 
-export
-HasErr e es => Exception e es where
-  throw err = MkApp $ MkAppRes (Left (findException %search err))
-  catch (MkApp prog) handler
+throw : HasErr err es => err -> App es a
+throw err = MkApp $ MkAppRes (Left (findException %search err))
+
+catch : HasErr err es => App es a -> (err -> App es a) -> App es a
+catch (MkApp prog) handler
       = MkApp $
            prim_app_bind prog $ \res =>
               case res of

tests/Main.idr

@@ -286,7 +286,8 @@ templateTests = MkTestPool "Test templates" [] Nothing
 -- available.
 baseLibraryTests : TestPool
 baseLibraryTests = MkTestPool "Base library" [Chez, Node] Nothing
-  [ "system_file001"
+  [ "control_app001"
+  , "system_file001"
   , "system_info_os001"
   , "system_system"
   , "data_bits001"

tests/base/control_app001/TestException.idr

@@ -0,0 +1,8 @@
+module TestException
+
+import Control.App
+
+throwBoth : Has [Exception String, Exception Int] es => App es ()
+
+throwOne : Has [Exception Int] es => App es Int
+throwOne {es} = handle {err = String} {e = es} throwBoth (\r => pure 1) (\e => pure 3)

tests/base/control_app001/expected

@@ -0,0 +1,3 @@
+1/1: Building TestException (TestException.idr)
+TestException> 
+Bye for now!

tests/base/control_app001/run

@@ -0,0 +1,3 @@
+$1 --no-color --console-width 0 --no-banner TestException.idr < input
+
+rm -rf build