Removes usages of zone-based helpers such as `fakeAsync` , `tick`
`waitForAsync` as part of the migration to zoneless tests.
Completes the transition to zoneless.
These helpers are often imported by various tests throughout the
repository, but the helpers aren't exported/exposed from the public
entry-point; even though they confusingly reside in there.
This commit fixes this, and moves the helpers into
`packages/private/testing`. This is a preparation for the `ts_project`
migration where we don't want to leverage deep imports between packages.
PR Close#61472
A lot of our tests are wrapped in `{}` which serves no purpose, aside from increasing the nesting level and, in some cases, causing confusion. The braces appear to be a leftover from a time when all tests were wrapped in a `function main() {}`. The function declaration was removed in #21053, but the braces remained, presumably because it was easier to search&replace for `function main()`, but not to remove the braces at the same time.
PR Close#52239
Jaime Burgos