Fix inability to display command names with whitespace in macOS

[whuang8]

Description

ps parsing in gotop is different for macOS and Linux because you can define column length on Linux but not on macOS. However, on macOS, the -o flag allows you to define custom headers. By setting a header to a specific length, we can recreate the Linux functionality of setting column widths.

header's width = column width

Now, parsing ps output can be the same as that defined in proc_linux.go

Fixes #107

[whuang8]

Definitely a bit of a hack to define column widths by the header 😅

Any thoughts?

[cjbassi]

Nice! This looks good. It is a little hacky, but I'd rather call that ingenuitive 😄

So you've tested this on OSX and its working for you?

Also, there was an issue where the command name was being cropped on OSX: #47 That was solved by adding the -ww flags, so maybe we don't need those anymore? Can you make sure both the command names and the full process names aren't being cropped with these changes and then try removing -ww and seeing if things are still good? The full process names are visible by pressing <Tab>. Thanks!

[whuang8]

I removed the -ww flags and tested this change on my Mac. The command names look goo and I can now see Google Chrome as well as other command names with white space.

I see this after pressing tab

Some process names after pressing tab are a little too long to fit in the panel. For example, take a look at Google Chrome Helper

If we take a look at these names with a bigger screen, more information shows up.

Maybe we can recreate htop's functionality of horizontal scroll with the ← → keys some time in the future?

[cjbassi]

Awesome, that looks good. Yah trimming the long process names is the expected behavior (for now) so that's fine, but maybe something to look into fixing in the future. Thanks a lot for the changes! Merging this and I'll try to create a release in a bit.