Refactor TerminalEmulatorTest

Make output less verbose by introducing a new method parseStreamData() in
TerminalEmulator that parses the general data stream without calling
update().
Refactor TerminalEmulatorTest

Make output less verbose by introducing a new method handleKeypress() in
TerminalEmulator that handles the pressed key without calling update().
TerminalEmulator only adds text key if inside field

TerminalEmulator only adds the pressed text key to the display buffer
if the cursor is inside an input field.
TerminalEmulator doesn't add text key if field is bypass