Some refactor on hop

[yehuohan]

Hop has beautiful and readable code with comment string for types. And this PR is to make some refactor to make hop better:

• add WindowRow,WindowCol,WindowCell and WindowChar to make hop position computation less confused
• make hop-treesitter and hop-yank as hop extensions according to hop framework
• add jump_regex.lua to make jump_target.lua thin
• add jump_target.move_jump_target to compute hint_offset (according to hop's comment, I think hint_offset wants to make offset by visible cells)
• add hop_helpers.lua to provide test functions for hop
• refactor: compute unmatched area with LineRange and ColumnRange
• refactor: remove MatchContext and make JumpContext thin (I think complete JumpContext and Options passed to Regex.match is better for hop-extension developement)
• fix: take the first folded line as an empty line, so we can jump to the first column of folded block too
• refactor: add clip_line_context and make jump_targets_by_scanning_lines thin
• refactor: add jump_target_generator to make creating Locations more easily and provide hop-extension ability to produce custom WindowContext[]

This is not a feature PR, but is to provide more typed and readable code instead.
@smoka7 Are you willing to review this PR?

[smoka7]

Hi! I had a quick look and it seems very good.All your proposed changes improve the code base and made it more consistent. Well done 👍.

Only problem is dimming unmatched lines is broken. for example :HopWordBC dims the line below the cursor.
it should be tested in

• empty lines
• first and last line of buffers
• first and last columns of a line
• include the cursor when dimming after or before cursor

[yehuohan]

@smoka7 My careless for dimming area. I refactored dimming related code, and now clip_window_context will give the correct area for advanced operations.

By the way, do you have any idea about what's the purpose of the add_virt_cur? I just have a better displayed cursor without add_virt_cur. (I tested on neovim-qt, neovide and nvy)

With add_virt_cur, sometime I got a double-cursor displayed:

Or a dark cursor:

[smoka7]

By the way, do you have any idea about what's the purpose of the add_virt_cur? I just have a better displayed cursor without add_virt_cur. (I tested on neovim-qt, neovide and nvy)

Nvim hides the cursor when it waits for user input while running getcharstr . The point of add_virt_cur is curing this. I've seen other plugins patch getcharstr to do similar thing to hop but I can think of any reason of its usefulness.

With add_virt_cur, sometime I got a double-cursor displayed:

Yes it happens on empty lines, it might be an Nvim issue. I think it's better to make it optional with default to false since it has a buggy behavior.