Add config to indicate the unicode support

[darshanasbg]

Proposed changes in this pull request

$subject. This config used in:

• https://github.com/wso2-extensions/identity-event-handler-notification/pull/284

This temporal config enable onboarding the change,

• https://github.com/wso2/carbon-identity-framework/pull/6120
• https://github.com/wso2-extensions/identity-event-handler-notification/pull/280 in a graceful manner when the previous schema is already in use.

Related to,

• https://github.com/wso2/product-is/issues/21235

When should this PR be merged

After merging https://github.com/wso2/carbon-identity-framework/pull/6120

Follow up actions

Merge

• https://github.com/wso2-extensions/identity-event-handler-notification/pull/284

[sonarcloud[bot]]

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[bot]]

Codecov Report

All modified and coverable lines are covered by tests :white_check_mark:

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

Additional details and impacted files

```diff @@ 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](https://app.codecov.io/gh/wso2/carbon-identity-framework/pull/6142/flags?src=pr&el=flags&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=wso2) | Coverage Δ | | |---|---|---| | [unit](https://app.codecov.io/gh/wso2/carbon-identity-framework/pull/6142/flags?src=pr&el=flag&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=wso2) | `25.61% <ø> (+0.02%)` | :arrow_up: | Flags with carried forward coverage won't be shown. [Click here](https://docs.codecov.io/docs/carryforward-flags?utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=wso2#carryforward-flags-in-the-pull-request-comment) to find out more.

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