feat: load session only once when middleware is used

[aeneasr]

Related issue(s)

Checklist

• I have read the contributing guidelines.
• I have referenced an issue containing the design document if my change
  introduces a new feature.
• I am following the
  contributing code guidelines.
• I have read the security policy.
• I confirm that this pull request does not address a security
  vulnerability. If this pull request addresses a security vulnerability, I
  confirm that I got the approval (please contact
  [email protected]) from the maintainers to push
  the changes.
• I have added tests that prove my fix is effective or that my feature
  works.
• I have added or changed the documentation.

Further Comments

[codecov]

Codecov Report

Attention: Patch coverage is 92.85714% with 1 line in your changes missing coverage. Please review.

Project coverage is 78.56%. Comparing base (ca0d6a7) to head (83ded88).
Report is 8 commits behind head on master.

Files with missing lines	Patch %	Lines
session/manager_http.go	83.33%	1 Missing ⚠️

Additional details and impacted files

@@           Coverage Diff           @@
##           master    #4187   +/-   ##
=======================================
  Coverage   78.56%   78.56%           
=======================================
  Files         380      380           
  Lines       27107    27114    +7     
=======================================
+ Hits        21297    21303    +6     
- Misses       4194     4195    +1     
  Partials     1616     1616           

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