Kobo: Refactor various aspects of the Kaleido/MTK support (#12221)

* UIManager: Let the fb backend deal with Kaleido wfm promotion. This fixes a number of quirks that poisoned the refresh queue with spurious full-screen refreshes. See https://github.com/koreader/koreader-base/pull/1865 for more details.
* This also means we now disable Kaleido waveform modes when color rendering is disabled (remember to trash your thumbnail cache if you don't want to mix color w/ grayscale thumbnails, though).
* UIManager: Merge refreshes that share an edge, because that was driving me nuts (and would have most likely been merged by the kernel anyway). A perfect test-case is the FM, which trips two separate refreshes because of its title bar.
* ReaderFlipping: Use sensible dimensions, so that we only refresh the icon's region.
* ReaderBookmark: Only refresh the dogear instead of the whole page when toggling bookmarks.
* NetworkSetting: Make it a real boy, so it consistently refreshes properly on dismiss instead of relying on UIManager saving the day.
* Kobo: Aggressively prevent *both* suspend & standby while MTK devices are plugged-in, as both will horribly implode the kernel (we previously only prevent standby while charging).
* Kobo: Switch to 8bpp on B&W MTK devices (or when color rendering is disabled on Kaleido panels).

frontend/apps/reader/modules/readerbookmark.lua

@@ -310,9 +310,15 @@ end
 
 function ReaderBookmark:onToggleBookmark()
     self:toggleBookmark()
-    self.view.footer:onUpdateFooter(self.view.footer_visible)
     self.view.dogear:onSetDogearVisibility(not self.view.dogear_visible)
-    UIManager:setDirty(self.view.dialog, "ui")
+    -- Refresh the dogear first, because it might inherit ReaderUI refresh hints.
+    UIManager:setDirty(self.view.dialog, function()
+        return "ui",
+        self.view.dogear:getRefreshRegion()
+    end)
+    -- And ask for a footer refresh, in case we have bookmark_count enabled.
+    -- Assuming the footer is visible, it'll request a refresh regardless, but the EPDC should optimize it out if no content actually changed.
+    self.view.footer:onUpdateFooter(self.view.footer_visible)
     return true
 end