fix(ssr): add missing methods from LightningElement @W-16614337

[wjhsf]

Details

This adds setAttribute and removeAttribute to the SSR implementation of LightningElement. It also adds stubs for methods that we may want to add in the future, so that we can more easily keep track of the gaps.

Does this pull request introduce a breaking change?

• 😮‍💨 No, it does not introduce a breaking change.
• 💔 Yes, it does introduce a breaking change.

Does this pull request introduce an observable change?

• 🤞 No, it does not introduce an observable change.
• 🔬 Yes, it does include an observable change.

GUS work item