fix content inset when keyboard is visible (#3207)

Task/Issue URL:
https://app.asana.com/0/392891325557410/1207990702991361/f
Tech Design URL:
CC:

**Description**:
Fix webview content inset when address bar is in bottom position.

**Steps to test this PR**:
1. Visit https://duck.ai with address bar in bottom and top position and
make sure the view adjusts accordingly.

DuckDuckGo/MainViewController.swift

@@ -613,6 +613,10 @@ class MainViewController: UIViewController {
 
         if self.appSettings.currentAddressBarPosition.isBottom {
             self.viewCoordinator.constraints.navigationBarContainerHeight.constant = max(52, keyboardHeight)
+
+            // Temporary fix, see https://app.asana.com/0/392891325557410/1207990702991361/f
+            self.currentTab?.webView.scrollView.contentInset = .init(top: 0, left: 0, bottom: keyboardHeight > 0 ? 52 : 0, right: 0)
+
             UIView.animate(withDuration: duration, delay: 0, options: animationCurve) {
                 self.viewCoordinator.navigationBarContainer.superview?.layoutIfNeeded()
             }