Left Nav Menu Changes

[Bonsai8863]

Proposed changes

• Made top-level left-nav text bolder to 600 weight
• Boosted opacity value for selected items
• Default submenu_show_icon to false

Checklist

• [x] I consider the submitted work as finished
• [x] I tested the code for its functionality
• [ ] I wrote test cases for the relevant uses case (coverage and e2e)
• [ ] I added/update the relevant documentation (either on github or on notion)
• [x] Where necessary I refactored code to improve the overall quality

Further comments

E2E automated tests are not necessary for a style change such as this.