[Amethyst: Feature/Bounty draft] Implement user-controlled client side filtering of notes.

Is your feature request related to a problem? Please describe:

There is no great way to search or filter followed npubs’ notes by various criteria. Searching and filtering unfollowed npubs is a harder problem for another day I believe, though maybe I’m wrong about that?

Describe the solution you'd like:

On the home screen users should be able to tap a filter/search icon and customize the notes they wish to see. For example:

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The filters should include a section for which npubs to include:

● probably defaulting to “all npubs followed by the user” which is like the current default view

● can also choose to filter down to just one or a subset of followed npubs

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The user should be able to choose what type of notes they want to see from the selected npubs:

● just posts:

>> Excludes replies

● in-my-network conversations:

>>Excludes replies except replies to npubs the user also follows

● all conversations / all posts and replies:

>>Includes every note signed by the npub

● just posts and replies including all the selected npubs

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The user should be able to filter by keyword. This is the hardest one I think because there are so many approaches especially when it’s more than one word.

● User should be able to (if following) select Jack’s npub (@npub1sg6plzptd64u62a878hep2kev88swjh3tw00gjsfl8f237lmu63q0uf63m), filter to all conversations, and filter with the keyword ‘nostrica’ for example to see all notes signed by this npub that include “nostrica”.

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More examples:

● Filtering down to a single npub and then ‘all conversations’ should result in a timeline of notes that combines the “Notes” and “Replies” sections when viewing that npub’s profile directly.

● Filtering down to a single npub and then ‘in-my-network conversations’ should result in a previously unavailable view of just that npub’s posts and replies to all the other npubs the user follows.

● Filtering down to two or more npubs (all followed by the user, in this case Vitor and Will) and then ‘just posts and replies including all the selected npubs’ should show just the notes and replies from the any of filtered npubs which include all the selected npubs. This could be used to see all the notes published by either #[0] (Vitor Pamplona) or #[1] (Will of Damus) that include both of their npubs, so basically just a view of their public nostr conversations.

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Obviously the naming of these labels and the UI/UX is a challenge. Ideally you could just type in natural language what you wanted to see and it would figure out the filters behind the scenes but I’m not sure I can fund a bounty for that level of feature..

Welcome any and all critiques #[2] #[0] et al.

Thanks