Fix screen rendering issues

[aarondfrancis]

No description provided.

[aarondfrancis]

Fixed a lot of the issues but still have a few cursor movement problems with Ngrok. Will need to capture some Ngrok output and try to make the emulator render it faithfully

[aarondfrancis]

This is not ready yet. There are still several failing tests. I think we'll have to switch to using arrays as the character buffer instead of strings.

[CamKem]

@aarondfrancis - Just pulled these latest changes; you're making some good ground on the fix.
I did however, noticed a couple of small things while putting it through its paces.

You may already be aware, either way I'll document here, in case your not & want to work on it this branch. Otherwise, I'm happy to add them in as seperate issues to be looked at once this fix is merged and we can work on it afterwards.

1. If you start / stop solo several times, occasionally on startup the About command loads pro scrolled 2 rows up.

2. On the heart & sheild emoji screens (2 of the 5) rendered by ngrok, the emoji and other text is malformed. Additionally rarely on render, left shifted line visibly not lining up on the right side too, but it's not readily repeatable.

[aarondfrancis]

@CamKem keep em coming! I think I've almost cracked it. I'll add tests for the "about" thing, and I've noticed one or two other line issues, so I miiiiight be able to isolate it

[aarondfrancis]

@CamKem I pulled part of your backspace fix from #72.

I added a few tests for backspace and delete, but weirdly the tests only pass without the replacement of the delete character. I'm not entirely sure what the correct behavior should be, but this matches the iTerm implementation.

You can see the diff here: 10a9e32

[aarondfrancis]

@CamKem you wanna put this through its paces before I merge it in? I think I fixed most of the issues (famous last words)

[CamKem]

@CamKem you wanna put this through its paces before I merge it in? I think I fixed most of the issues (famous last words)

@aarondfrancis looks pretty good, however still a couple of issues persisting. Honestly they maybe edge cases that the time invested would outweigh the benefit gained at this point, i'll leave that up to you. Alternatively we can add these as seperate issues to be worked on after this is merged, so you can tag a more stable release with the work you have done.

1. If you run & quit the solo multiple times, on occasion the about command will render with the top line not being rendered.

2. When the terminal is smallish (but not small enough to cause line breaks), there is a slight rendering issue with the ascii logo art (early break?)

3. Grrr ngrok! There is persistent issues with the ❤️ & 🛡️ emojis which represent 2 out of a possible 5 screens that ngrok can render.

4. Sometimes the top line of the ngrok screen doesn't complete the background row.

[CamKem]

@CamKem I pulled part of your backspace fix from #72.

I added a few tests for backspace and delete, but weirdly the tests only pass without the replacement of the delete character. I'm not entirely sure what the correct behavior should be, but this matches the iTerm implementation.

You can see the diff here: 10a9e32

@aarondfrancis - Interesting, I went off the VT100 / GNUReadline key mappings (https://www.gnu.org/software/bash/manual/html_node/Readline-Bare-Essentials.html) which should work as the screen is a VT100 emulator using the GNUReadline key mappings.

Thanks for the heads up, can look further into it on my PR if need be.