Add 'less' Text Pagination Functionality to Dynamically View Parts of Large Text

[nnh12]

This PR restores the less functionality. This displays a small section of text at a time to make viewing large files easier and interactively via the Up and Down key.

Note: Previous implementation relied on app_io to grab a reference to the current terminal and keyboard. However, app_io::get_my_terminal() and app_io::take_key_event_queue() can no longer be supported or re-added due to code structuring. This is why I added the code to the shell application, which already has access to the current terminal and keyboard.

Use the Up and Down key to scroll through text and Q key to quit less mode. Below are some test cases. I added opning_crawl_all.txt for a large file for test.

/extra_files/test_files/text/ : less opening_crawl_all.txt

(Used Down arrow key to scroll through rest of text).

It is a period of civil war.
Rebel spaceships, striking
from a hidden base, have won
their first victory against
the evil Galactic Empire.

During the battle, Rebel
spies managed to steal secret
plans to the Empire's
ultimate weapon, the DEATH
STAR, an armored space
station with enough power to
destroy an entire planet.
...
...

Rebel spaceships, striking
from a hidden base, have won
their first victory against
the evil Galactic Empire.

During the battle, Rebel
spies managed to steal secret
plans to the Empire's
ultimate weapon, the DEATH
STAR, an armored space
station with enough power to
destroy an entire planet.

...
...

from a hidden base, have won
their first victory against
the evil Galactic Empire.

During the battle, Rebel
spies managed to steal secret
plans to the Empire's
ultimate weapon, the DEATH
STAR, an armored space
station with enough power to
destroy an entire planet.

Pursued by the Empire's
...
...

(Using Up key to scroll up).

Rebel spaceships, striking
from a hidden base, have won
their first victory against
the evil Galactic Empire.

During the battle, Rebel
spies managed to steal secret
plans to the Empire's
ultimate weapon, the DEATH
STAR, an armored space
station with enough power to
destroy an entire planet.

...
...