Signup/Login + styling adjustments

- Modified SearchBar styling
- Modified TopBar to display blank circle if the user has no networks (previously missing image icon)
- Refactored Login into AuthPage.js
- AuthPage contains a tab selector for switching between Signup and Login
- Both Login/Signup send the request and either receive an auth_token or an error message
- If auth_token, user will be logged in as usual, in both cases
- Signup validates user input before sending request
- Added /signup target in vite config file

src/components/SearchBar.js

@@ -1,6 +1,6 @@
 css(`
     searchbar- input::placeholder {
-      color: #5C504D
+      color: #5C504D;
     }
 `)
 
@@ -36,7 +36,7 @@ class SearchBar extends Shadow {
         .paddingVertical(0.75, em)
         .boxSizing("border-box")
         .paddingHorizontal(1, em)
-        .background("var(--darkaccent)")
+        .background("var(--searchbackground)")
         .color("var(--accent)")
         .marginBottom(1, em)
         .border("1px solid var(--accent)")