Allow hiding UI elements via configuration options.

Is your feature request related to a problem? Please describe. I find the lnav UI really cluttered for my simple use cases (mostly reading json log files).

Describe the solution you'd like I would like to be able to hide:

• The top status bar containing the clock. (Looks like there is a PR for this, #1732)
• The bottom status bar showing the line count and other info.
• Keybind hints in the top and bottom status bar.
• Possibly use the space from the hidden hints to display line count and search info.

This would make the UI only show the breadcrumb bar, the configuration panels bar and the prompt.

Describe alternatives you've considered I tried lo-fi display, but the view is not scrollable.

Additional context By keybind hints I mean messages like:

• Press ` to focus on the breadcrumb bar
• Press TAB to edit
• ?:View Help
• Press e/E to move forward/backward through error messages