Fix multi-value attribute encoding for non-ASCII characters

[Copilot]

Description

When an LDAP attribute has multiple values containing non-ASCII characters, only the first value was returned. The processAttribute method was using attribute.getValueByteArray() (singular) which only returns the first value's byte array, ignoring subsequent values.

Changes:

• Modified processAttribute to use getValueByteArrays() (plural) and iterate all values when Base64 encoding is required
• Refactored encodeAttributeValue to accept attribute name and byte array separately
• Added encodeAttributeValues helper for batch encoding
• Added null/empty array safety checks
• Added changelog.md with release note entry linking to the issue

One line release note:

• Fixed multi-value LDAP attributes with non-ASCII characters returning only the first encoded value

Type of change

• Bug fix (non-breaking change which fixes an issue)

How Has This Been Tested?

• Added testMultiValueAttributeWithNonAscii test that creates an entry with multi-value description attribute containing Japanese, Greek, and Chinese characters, then verifies all 3 values are returned

Test Configuration:

• Ballerina Version: SwanLake Update 12
• Operating System: Linux
• Java SDK: 17

Checklist:

Security checks

• Followed secure coding standards in http://wso2.com/technical-reports/wso2-secure-engineering-guidelines?
• Confirmed that this PR doesn't commit any keys, passwords, tokens, usernames, or other secrets?

Original prompt

You are an software enginner familiar with Ballerina, Java and LDAP specification

Fix the issue descriped in ballerina-platform/ballerina-library#8562

Make sure to add proper test cases

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[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
⚠️ Please upload report for BASE (fix-bug-8562@4202650). Learn more about missing BASE report.

Additional details and impacted files

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  Hits                    ?       29           
  Misses                  ?        1           
  Partials                ?        0           

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[TharmiganK]

@copilot Add a change log file similar to this: https://github.com/ballerina-platform/module-ballerina-http/blob/master/changelog.md where you add a one line change and link the issue

[Copilot]

@copilot Add a change log file similar to this: https://github.com/ballerina-platform/module-ballerina-http/blob/master/changelog.md where you add a one line change and link the issue

Added changelog.md with a one-line change note linking to issue #8562 in commit 0cf5bcc.