moved service page and service field to page API

scripts/api/page/servicepage.lua

@@ -2,7 +2,7 @@ require("common.class")
 local Dim = require("common.dimensions")
 local Util = require("common.util")
 local Page = require("api.page.page")
-local ServiceField = require("titlescreen.components.servicefield")
+local ServiceField = require("api.page.servicefield")
 
 ---@class ServicePage: Page
 ---@field title string|string[]
@@ -52,7 +52,7 @@ function ServicePage:refreshFields()
         if index == self.selectedIndex then
             field:focus()
         else
-            field:deactivate()
+            field:unfocus()
         end
     end
     Page.refreshFields(self)
@@ -72,9 +72,7 @@ function ServicePage:handleButtonInput(button)
     local direction = 0
 
     if button == game.BUTTON_BCK then
-        if self.viewHandler then
-            self.viewHandler:back()
-        end
+        self:onInvalidation()
         return
     elseif button == game.BUTTON_BTA then
         direction = -1
@@ -83,7 +81,7 @@ function ServicePage:handleButtonInput(button)
     end
 
     if direction ~= 0 then
-        field:deactivate()
+        field:unfocus()
 
         self.selectedIndex = Util.modIndex(self.selectedIndex + direction, #self.content)