Chunk deferred runtime and terminal modules in Web IDE

• Revert async loading components in ide.vue
• Chunk deferred runtime and terminal modules in Web IDE
• Add docs for potential test timeout issue

What does this MR do?

This MR:

1. Reverts async importing all the deferred things in ide.vue since some of these are really small or are already included in the main bundle.
2. Only async imports the components that are really not needed until runtime in one ide_runtime chunk.
3. Adds an async import to the terminal session component which generates a big chunk (see relevant note).

Network activity on /-/ide/project/flightjs/flight/tree/master

What?	Before (on master)	After (this MR)
JS / All requests	19 / 43	17 / 40
JS / All transferred	40.5 MB / 43.5 MB	39.5 MB / 42.5 MB

Network activity on /-/ide/project/flightjs/flight/tree/master/-/ADOPTERS.md/

What?	Before (on master)	After (this MR)
JS / All requests	21 / 50	18 / 47
JS / All transferred	40.6 MB / 45.0 MB	39.6 MB / 43.8 MB

Waterfall

Before (on master)	After (this MR)

Big takeaway from Waterfall

You'll notice that the pages.ide.chunk.js bundle is not always the bottleneck to kicking things off. The most significant bottleneck is the monaco.chunk.js. This means that if we move too much from pages.ide.chunk we could end up shooting ourselves in the foot because we'd end up loading these things after monaco.chunk.js is loaded rather than during.

Screenshots (strongly suggested)

Terminal still loads 🎉	In a separate chunk 🎉

Does this MR meet the acceptance criteria?

Conformity

• Changelog entry
• Documentation (if required)
• Code review guidelines
• Merge request performance guidelines
• Style guides
• Database guides
• Separation of EE specific content