chore: WDS colors `bdNeutral` and `bdNeutralHover`

[ichik]

Description

tl;dr Fixed APCA contrast checks and logic for bdNeutral, fixed bdAccent check too (see also #23218 for more stuff to fix). Adjusted gradations of hover for the color to make it visible in both modes.

Fixes #22823

Media

New on the left, current on the right (using the latest DP instead of release deploy, since it's failing at the moment of creation of this PR) https://github.com/appsmithorg/appsmith/assets/80973/cfcb7aa7-17cd-454d-a452-779efba20158

Type of change

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Chore (housekeeping or task changes that don't impact user perception)

How Has This Been Tested?

• Manual

Test Plan

Initial POC refinement, no testing necessary

Checklist:

Dev activity

• [x] My code follows the style guidelines of this project
• [x] I have performed a self-review of my own code
• [ ] I have commented my code, particularly in hard-to-understand areas
• [ ] I have made corresponding changes to the documentation
• [x] My changes generate no new warnings
• [ ] I have added tests that prove my fix is effective or that my feature works
• [ ] New and existing unit tests pass locally with my changes
• [ ] PR is being merged under a feature flag

QA activity:

• [ ] Test plan has been approved by relevant developers
• [ ] Test plan has been peer reviewed by QA
• [ ] Cypress test cases have been added and approved by either SDET or manual QA
• [ ] Organized project review call with relevant stakeholders after Round 1/2 of QA
• [ ] Added Test Plan Approved label after reveiwing all Cypress test