WebDAV cache: re-factor using Guava and Hilt

[rfc2822]

Currently we have some custom cache implementations that can be replaced by Guava functionality (now as we have the Guava dependency).

• Use component-wide Guava cache for HeadResponseCache
  • Allows to remove ExtendedLruCache
• Use per-resource Guava cache as a loading page cache
  • Allows to replace PageLoader by guava.CacheLoader<*>
  • Page size limit increased to 10, but with SoftReference values, so they will be GC-ed if necessary
• Move RandomAccessCallbackWrapper to outer class for better readability and because it has it's own responsibility
• Use Hilt for DI