[backend] bring back deprecated routes to let agents upgrade (#2247)

[guillaumejparis]

Proposed changes

Related issues

• Closes OpenBAS server user interface does not show agent version #2247

Checklist

• I consider the submitted work as finished
• I tested the code for its functionality
• I wrote test cases for the relevant uses case
• I added/update the relevant documentation (either on github or on notion)
• Where necessary I refactored code to improve the overall quality
• For bug fix -> I implemented a test that covers the bug

Further comments

If this is a relatively large or complex change, kick off the discussion by explaining why you chose the solution you did and what alternatives you considered, etc...

[codecov]

Codecov Report

Attention: Patch coverage is 0% with 4 lines in your changes missing coverage. Please review.

Project coverage is 32.69%. Comparing base (e5dfd5a) to head (3a31301).
Report is 1 commits behind head on master.

Files with missing lines	Patch %	Lines
...va/io/openbas/rest/asset/endpoint/EndpointApi.java	0.00%	4 Missing ⚠️

Additional details and impacted files

@@             Coverage Diff              @@
##             master    #2258      +/-   ##
============================================
- Coverage     32.70%   32.69%   -0.01%     
  Complexity     1515     1515              
============================================
  Files           582      582              
  Lines         18038    18042       +4     
  Branches       1156     1156              
============================================
  Hits           5899     5899              
- Misses        11875    11879       +4     
  Partials        264      264              

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