Begin refactoring gui

This begins a big refactor of moving more code out of the Gui struct into contexts, controllers, and helpers. We also move some code into structs in the
gui package purely for the sake of better encapsulation

pkg/gui/controllers/helpers/view_helper.go

@@ -0,0 +1,33 @@
+package helpers
+
+import (
+	"github.com/jesseduffield/lazygit/pkg/gui/context"
+	"github.com/jesseduffield/lazygit/pkg/gui/types"
+)
+
+type ViewHelper struct {
+	c        *types.HelperCommon
+	contexts *context.ContextTree
+}
+
+func NewViewHelper(c *types.HelperCommon, contexts *context.ContextTree) *ViewHelper {
+	return &ViewHelper{
+		c:        c,
+		contexts: contexts,
+	}
+}
+
+func (self *ViewHelper) ContextForView(viewName string) (types.Context, bool) {
+	view, err := self.c.GocuiGui().View(viewName)
+	if err != nil {
+		return nil, false
+	}
+
+	for _, context := range self.contexts.Flatten() {
+		if context.GetViewName() == view.Name() {
+			return context, true
+		}
+	}
+
+	return nil, false
+}