Delete 'etc' folder and improve power config handling code

[chernyee]

Motivate of the pull request

• To address an existing issue. If so, please provide a link to the issue:
• Breaking new feature. If so, please describe details in the description part.

Describe the technical details

Changes:

• Improve Device Power Config to handle optional resources
• Delete the 'etc' folder which contains the device power config files
• Remove hardcoded resources used for development purpose

Which part of the code base require a change

• Frontend:
• Backend: PowerCfg Module
• Library: <Specify the library name, e.g. npm packages>
• Plug-in: <Specify the plugin name, e.g. Webpack, jtest>
• Documentation
• Regression tests
• Continuous Integration (CI) scripts

[codecov]

Codecov Report

Attention: Patch coverage is 25.24272% with 77 lines in your changes missing coverage. Please review.

Project coverage is 68.83%. Comparing base (efcd133) to head (7d553c7).
Report is 1 commits behind head on main.

Files with missing lines	Patch %	Lines
backend/submodule/io.py	14.70%	29 Missing ⚠️
backend/submodule/bram.py	22.22%	21 Missing ⚠️
backend/submodule/dsp.py	23.07%	20 Missing ⚠️
backend/submodule/peripherals.py	0.00%	3 Missing ⚠️
backend/submodule/rs_device_resources.py	57.14%	3 Missing ⚠️
backend/submodule/rs_device.py	0.00%	1 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main     #254      +/-   ##
==========================================
+ Coverage   68.67%   68.83%   +0.15%     
==========================================
  Files         110      110              
  Lines        9045     9022      -23     
  Branches      402      402              
==========================================
- Hits         6212     6210       -2     
+ Misses       2833     2812      -21     

☔ View full report in Codecov by Sentry.
📢 Have feedback on the report? Share it here.