[ic-side-navigation] Long nav items get cut off + tooltips display when expanded

Summary of the bug

When you have a long nav item inside side nav and the side nav is collapsed by default, then it doesn't correctly calculate the height for the long nav item. It's just restricting it to whatever the default height is (which I think is 56px ish).

Additionally, tooltips appear next to nav-items when the side-nav is expanded, they should only appear when the side nav is collapsed. This should be addressed in this ticket too.

🪜 How to reproduce

Tell us the steps to reproduce the problem:

1. Go to side nav example with long nav item
2. Open the side nav
3. See the error (text overflowing nav-item, being obscured) and how tooltips still appear next to nav-items)
4. Open the story below it where the side nav is expanded by default, and see that the long nav item appears correctly

• Tooltips appear if you collapse and re-expand the side nav, which is incorrect.

📸 Screenshots or code

🖥 📱 Device

• Type: Desktop
• Browser: Chrome

🧐 Expected behaviour

It should appear the same whether it's expanded by default or not.

Additional info

Should probably add a Cypress test for this as it's alarming we haven't noticed it.

Start with the linked side-navigation stories and reproduce the issue in Chrome, then trace the side-navigation implementation used by those examples. Add the suggested Cypress regression coverage; it is done when long nav items display correctly in both initial states and tooltips appear only while the side nav is collapsed.