* Due to linking errors with libkiwix/libzim functions, direct usage in testing was not possible. To address this, helper classes were created, similar to those in `java-libkiwix`, for testing the search functionality.
* With the integration of libkiwix12, we now receive full results based on the search term. Previously, we were loading the entire list, but we have now implemented pagination to enhance the search functionality.
* The libkiwix provides us with a Search object, which enables us to obtain the suggestion list using start and end indices. Consequently, we have modified our `ZimSearchResultGenerator` code to return the `Search` object instead of a list.
* To accommodate the changes, we have updated the return type of `SearchResultGenerator` to a nullable Search. This change is necessary because we initialize the `SearchState` when the search is initialized in `SearchViewModel`, and initially, we do not have the Search object available. The nullable return type allows us to pass the Search object when it becomes available.
* Since our minimum API level is now 24, we have updated our CI configuration to run on API level 24, which aligns with the minimum API level required for our project.
* Now our minimum SDK version is 24 and we are using some conditions placed on behalf of this api level which are unused now, so we have removed those conditions.
* Removed `CompatV21` file as now it is unused.
* Renamed `CompatV23` to `CompatV24` and refactored the code to support our new minimum api level.
* Refactored `NetworkUtilsTest` to support api level 24.
* As we can not search in that zim file which is not contains the FT Xapian index and testzim.zim file is not contain it so we have improved our test case.
* Now we are downloading the `off the grid` zim file and performing the search functionality inside it.
* Previously we can only open zim files from `USB-OTG` in android 10 and below devices, because `context.getExternalFilesDirs("")` does not provide the USB path in android 10 and above devices for security reasons. There is no direct way to access the USB-OTG on these devices, but USB-OTG are mounted under the `/mnt/media_rw` directory, so now we are directly using this to open zim files from USB drive for android 10 and above devices.
* Added `tmpfs` filesystem to `support 4GB filesystem list` since this type supports writing files over 4GB.
* Updated the name of the writing test result file to `kiwix_4gb_writing_test_result` to enhance readability.
* When any article is loading then we invalidate the `OptionMenu` from `KiwixWebChromeClient` (It does not check whether the fragment is visible or not) which also invalidates the toolbar and the search bar is inside the toolbar that's the reason the keyboard showing and hiding repeatedly.
* Now we are invalidating the `OptionMenu` inside the `CoreReaderFragment` when it is visible to the user since this fragment loads the content in the webview. Hence, it is better to update the UI when it is visible to the user so it would not affect any other UI part.
* Added pause/resume button beside the stop button to perform pause/resume action on the downloading zim file.
* Handling pause/resume via fetch library.
