Add config to indicate the unicode support

[darshanasbg]

Proposed changes in this pull request

$subject. This config used in:

• Store content based on the unicode support flag wso2-extensions/identity-event-handler-notification#284

This temporal config enable onboarding the change,

• Store notification content as binary to support unicode #6120
• Store notification content as binary to support unicode wso2-extensions/identity-event-handler-notification#280
  in a graceful manner when the previous schema is already in use.

Related to,

• Have the ability to support non-latin unicode characters for email templates product-is#21235

When should this PR be merged

After merging #6120

Follow up actions

Merge

• Store content based on the unicode support flag wso2-extensions/identity-event-handler-notification#284

[sonarqubecloud]

Quality Gate passed

Issues
0 New issues
0 Accepted issues

Measures
0 Security Hotspots
0.0% Coverage on New Code
0.0% Duplication on New Code

See analysis details on SonarQube Cloud

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 41.19%. Comparing base (b1ebad7) to head (e00802e).
Report is 13 commits behind head on master.

Additional details and impacted files

@@             Coverage Diff              @@
##             master    #6142      +/-   ##
============================================
- Coverage     41.28%   41.19%   -0.10%     
+ Complexity    15009    14734     -275     
============================================
  Files          1775     1775              
  Lines        121330   118350    -2980     
  Branches      20239    19661     -578     
============================================
- Hits          50095    48752    -1343     
+ Misses        63771    62261    -1510     
+ Partials       7464     7337     -127     

Flag	Coverage Δ
unit	25.61% <ø> (+0.02%)	⬆️

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