* Add getRealFullName() to ClassNode and JavaClass and searchJavaClassByRealName() to JadxWrapper

Those methods is like getFullName() and searchJavaClassByClassName(), but for class names without aliases.
It is necessary for renaming classes/methods/fields.

* core: Make getFieldNode(), getMethodNode() and getRoot() public

This is necessary for renaming functionality

* jadx-gui: Add Rename popup menu entry (renames classes, methods and fields)

It allows user to rename classes, methods and fields.
It updates deobfuscation map and reload file.
This may be suboptimal, and maybe some RenameVisitor should be added.
Deobfuscation should be enabled in order to allow this.