fix: automate eitherize methods

Signed-off-by: Dr. Carsten Leue <carsten.leue@de.ibm.com>

context/readerioeither/generic/cancel.go

@@ -0,0 +1,19 @@
+package generic
+
+import (
+	"context"
+
+	CIOE "github.com/ibm/fp-go/context/ioeither/generic"
+	E "github.com/ibm/fp-go/either"
+	IOE "github.com/ibm/fp-go/ioeither/generic"
+)
+
+// withContext wraps an existing ReaderIOEither and performs a context check for cancellation before delegating
+func WithContext[GRA ~func(context.Context) GIOA, GIOA ~func() E.Either[error, A], A any](ma GRA) GRA {
+	return func(ctx context.Context) GIOA {
+		if err := context.Cause(ctx); err != nil {
+			return IOE.Left[GIOA](err)
+		}
+		return CIOE.WithContext(ctx, ma(ctx))
+	}
+}