fix(Menu): Nested menu parent item background and click

[mdodgelooker]

A couple fixes on a nested menu parent item:

1. The nested menu opens on hover but a user could easily assume they need to click to open it. If they do this, it opens briefly when they hover then quickly closes when they click. I thought this was a regression but apparently we did this intentionally without thinking of this scenario.
2. Awhile back the aria-selected prop was moved to ListItemContent but the associated background style was not.

[github-actions[bot]]

Coverage report

Total coverage

Status	Category	Percentage	Covered / Total
🟢	Statements	94.84%	7301/7698
🟡	Branches	87.16%	4650/5335
🟢	Functions	93.63%	2102/2245
🟢	Lines	95.38%	7065/7407

Status of coverage: 🟢 - ok, 🟡 - slightly more than threshold, 🔴 - under the threshold

Show files with reduced coverage 🔻

### Reduced coverage | Status | Filename | Statements | Branches | Functions | Lines | | :----: | :------------------------------------ | :--------- | :------- | :-------- | :---- | | 🟡 | components/src/Menu/useNestedMenu.tsx | 88.89% | 68.09% | 100% | 90% | > Status of coverage: 🟢 - ok, 🟡 - slightly more than threshold, 🔴 - under the threshold

Report generated by 🧪jest coverage report action from 75c3301e6dbf74e60d120950cdd31cf4af267406

[mdodgelooker]

Oops, I messed up Tree with my aria-expanded fix. Stay tuned...

[mdodgelooker]

Ok sorry about that. I just re-did the aria-expanded style fix but this time without breaking lint or snapshots. 🙂