Have you looked into the [Name Panel Addon][1]

It's a payed commercial addon, but it is open source, hosted on [GitHub][2] and you can also buy it from the [Blender Market][3] if you wish to show support for the developer.

It is quite a versatile extension, with cabale batch renaming functions for objetcs, materials textures, groups etc.

It also has good batch name copy/transfer and additional UI features for selection and filtering.

Among that it also includes an advanced bone renaming, including armatures, bones and constraints, automatic name generator.

I am not affiliated in any way with the addon or author, although I do am a happy user.


  [1]: https://blenderartists.org/forum/showthread.php?272086-Addon-Name-Panel-1-7
  [2]: https://github.com/proxeIO/name-panel/issues
  [3]: https://blendermarket.com/products/name-panel