The language service reports an error when a directive's template
context is missing a member that is being used in a template (e.g. if
`$implicit` is being used with a template context typed as `any`).
While this diagnostic message is valuable, typing template contexts
loosely as `any` or `object` is very widespread in community packages,
and often still compiles correctly, so reporting the diagnostic as an
error may be misleading to users.
This commit changes the diagnostic to be a warning, and adds additional
information about how the user can eliminate the warning entirely -- by
refining the template context type.
Closes https://github.com/angular/vscode-ng-language-service/issues/572
PR Close#35036