key_binder: add whences first_page, not_first_page, last_page, not_last_page

[fxliang]

Pull request

Issue tracker

Fixes will automatically close the related issue

Fixes #

Feature

Describe feature of pull request
add whences: first_page, not_first_page, last_page, not_last_page

it would be helpful when pattern like recognizer/patterns/money: '^/dx\d+(\.\d{0,2})?$' is set, when comma / period is binding to page up / page down.

    - { when: paging, accept: comma, send: Page_Up }
    - { when: not_last_page, accept: period, send: Page_Down }

Unit test

• Done

Manual test

• Done

Code Review

1. Unit and manual test pass
2. GitHub Action CI pass
3. At least one contributor reviews and votes
4. Can be merged clean without conflicts
5. PR will be merged by rebase upstream base

Additional Info