Improve pagination usability

[gtsiolis]

Problem to solve

Following the introduction of the pagination component back in https://github.com/gitpod-io/gitpod/pull/11481 and the improvements in https://github.com/gitpod-io/gitpod/pull/11800 (thanks @laushinka!), the component usability and designs could be improved in a following iteration.

For example:

1. Use the while button area as an active hover area instead of just the number
2. Use the same color for the arrow and the button label for next and previous buttons
3. Use hover and active states in terms of color
4. Update button height, font weight, etc to match the initial design specs

CURRENT	DESIGN SPECS