New Feature: Search Functionality

I have added search functionality to snap, which allows for users to search for blocks by name. I made a input string morph and a push button morph that are located under the categories amd above the palette. It works for all standard, and custom blocks, as well as variables, push buttons, and toggles. Search works in all supported languages.  There are two issues I still have, which are that the toggles do not refresh after they are clicked, and the search button's text is not initially centered in the button.