Remove unnecessary private method `getDeclarationFromNode` and moved
some logic to utils instead so that it can be tested in isolation of the
Language Service infrastructure.
The use of typechecker to check the directive is also not necessary,
since resolve.getNonNormalizedDirectiveMetadata() will check if the
directive is actually an Angular entity.
PR Close#32156
This commit creates two concrete classes Inline and External
TemplateSource to differentiate between templates in TS file and
HTML file.
Knowing the template type makes the code much more explicit which
filetype we are dealing with.
With these two classes, there is no need for `getTemplateAt()` method in
TypeScriptHost. Removing this method is safe since it is not used in the
extension. This reduces the API surface of TypescriptHost.
PR Close#32127
Keen Yee Liau