606 Update pagination active page button colour

[Dev-Akashili]

Changes

This changes the colour of the button indicating an active page, to blue so it is clearer to see. Resolves #606

Checks

Important: please complete these before merging.

• [x] Run migrations, if any.
• [x] Update changelog.md, including migration instructions if any.
• [x] Run unit tests.

[AndyRae]

There's more than one pagination use (rules table), so find them all and change them also. The primary blue would ideally be the Co Connect brand blue like the rest of the button And reference the issue this closes in the description #606 - https://docs.github.com/en/issues/tracking-your-work-with-issues/linking-a-pull-request-to-an-issue#linking-a-pull-request-to-an-issue-using-a-keyword