Previously we only checked for static import declaration statements.
This commit also finds import paths from dynamic import expressions.
Also this commit should speed up processing: Previously we were parsing
the source code contents into a `ts.SourceFile` and then walking the parsed
AST to find import paths.
Generating an AST is unnecessary work and it is faster and creates less
memory pressure to just scan the source code contents with the TypeScript
scanner, identifying import paths from the tokens.
PR Close#37075