[Bedrock] Move ExclusiveAccessManager to BrowserWindowFeatures

This CL moves ExclusiveAccessManager off Browser and into
BrowserWindowFeatures.

Some other code related to DownloadBubbleUIController initialization
was moved into BrowserWindowFeatures::InitPostWindowConstruction, just
after ExclusiveAccessManager creation, because it needed
ExclusiveAccessManager to be initialized to get FullScreenController
that it depended on. Also bypassed DownloadBubbleUIController and
directly used download_toolbar_ui_controller_->display_controller().

ExclusiveAccessManager was initialized early in BrowserWindowFeatures::
InitPostWindowConstruction because LensOverlayEntryPointController::
Initialize also needed FullScreenController initialization to be done
by ExclusiveAccessManager.

The remaining changes involved mostly about adding
browser_window_features.h header to most source files and adding
//chrome/browser/ui/browser_window as dependency in the corresponding
BUILD.gn files.

Bug: 418896085

Change-Id: I7188d1c7def87fa2332750b0b1bf1f5b1df85af9
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/6635380
Reviewed-by: Hidehiko Abe <hidehiko@chromium.org>
Commit-Queue: Chandranath Bhattacharyya <chbhatt@microsoft.com>
Reviewed-by: Tom Lukaszewicz <tluk@chromium.org>
Cr-Commit-Position: refs/heads/main@{#1476659}