Simplify yield delegation process.

[clement-ux]

Description

After multiple months of experience, managing delegateYield() and undelegateYield() through governance has turned out to be a pain point. This PR aims to reduce that friction by allowing the strategist to call these two functions.
This does not reduce security, as the only potential impact of a rogue strategist would be causing a user to lose yield.

Code Change Checklist

To be completed before internal review begins:

• The contract code is complete
• Executable deployment file
• Fork tests that test after the deployment file runs
• Unit tests *if needed
• The owner has done a full checklist review of the code + tests

Internal review:

• Two approvals by internal reviewers

[github-actions]

	Warnings
⚠️	👀 This PR needs at least 2 reviewers

Generated by 🚫 dangerJS against 0d74f10

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 41.24%. Comparing base (bfea30c) to head (0d74f10).
Report is 3 commits behind head on clement/manage-EIP-7702-for-OUSD.

Additional details and impacted files

@@                         Coverage Diff                          @@
##           clement/manage-EIP-7702-for-OUSD    #2544      +/-   ##
====================================================================
+ Coverage                             41.18%   41.24%   +0.05%     
====================================================================
  Files                                   106      106              
  Lines                                  4956     4961       +5     
  Branches                               1302     1304       +2     
====================================================================
+ Hits                                   2041     2046       +5     
  Misses                                 2913     2913              
  Partials                                  2        2              

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

🚀 New features to boost your workflow:

• ❄️ Test Analytics: Detect flaky tests, report on failures, and find test suite problems.
• 📦 JS Bundle Analysis: Save yourself from yourself by tracking and limiting bundle sizes in JS merges.