feat(common): implement DumbAware interface in AbstractFileIconProvider

- Make AbstractFileIconProvider DumbAware to prevent issues during indexing.
- Ensure consistent formatting in README.md.
- Add YourKit sponsorship acknowledgment in README.md.

README.md

@@ -117,6 +117,6 @@ Contributions of any kind welcome!
 ![YourKit](https://www.yourkit.com/images/yklogo.png)
 
 YourKit supports open source projects with its full-featured Java Profiler.
-YourKit, LLC is the creator of https://www.yourkit.com/java/profiler/YourKit Java Profiler]
-and https://www.yourkit.com/.net/profiler/YourKit .NET Profiler],
+YourKit, LLC is the creator of https://www.yourkit.com/java/profiler/ Java Profiler]
+and https://www.yourkit.com/dotnet-profiler/ .NET Profiler],
 innovative and intelligent tools for profiling Java and .NET applications.