fix(icons): Updates to clock-related icons

[jamiemlaw]

What is the purpose of this pull request?

• [ ] New Icon
• [ ] Bug fix
• [ ] New Feature
• [ ] Documentation update
• [x] Other: icon updates and optimisations

Description

This PR address a couple of inconsistencies and adds some optimisations to the clock-related icons

• All the base clock-icons originally used <polyline/>s for the hands, which are now converted to <path/>s
• The hour hands of the 2-, 4-, 8-, and 10 o'clock icons have angles that better match those of the 1-, 5-, 7- and 11 o'clock icons
• Icons that use a small clock face are now all consistent with each other, and resolves a two-pixel-gap violation for some

Before Submitting

• [x] I've read the Contribution Guidelines.
• [x] I've checked if there was an existing PR that solves the same issue.