Add a basic excluded-processes-list in btop before btop starts to reduce number of shown processes on btop start

[ClearFate]

When launching btop - btop shows all the processes running and that makes it hard to look for new previously not running processes. The only way to filter processes is by using filter 'f' key but that serves to find specific process.

I'd like a feature where us users could have option to add exclude-process-list.yaml (or any other format just not json because it doesn't support comments) that btop could use when starting to filter against that list and not display those processes we deemed 'safe' and we don't care about to monitor right now. maybe also expose a flag/ argument when running btop --exclude and maybe a property alwaysUseExcludeList=true.

The way I see it those exclude lists could be used in various ways but for example one use case: paranoid user just installed minimal arch labwc setup. Goes over processes running currently on fresh OS install one by one and adds those processes to his exclude-process-list in .config/btop so now his btop shows only things he want's to see not everything cluttered. If he spots unusual process/es (maybe after package install and service add) he can instantly see which ones are extra and check if they're valid/safe.

If user doesn't add property alwaysUseExcludeList then excluded processes way of seeing things would only be one of cycle process screens that user can go to. Important to note that exclude processes are user reduced set of processes that can still be filtered through with 'f' just the processes set is smaller.

[ClearFate]

for example i don't really care about these system processes and I'd like to auto hide them when btop starts

[deckstose]

for example i don't really care about these system processes and I'd like to auto hide them when btop starts

For these specific processes, there is an option in Esc -> Options -> Proc -> Proc filter kernel that removes kernel threads from the list.

[ClearFate]

That only partially solves the described problem, there's also non kernel processes that are cluttering the process view.

[deckstose]

Related, maybe duplicate of #1054. Otherwise I don't see a way how we would implement this. A new config file in a format we don't support is very unlikely.