feat: support rabbitmq headers

[DaAlbrecht]

Purpose

This pull request adds the ability to include custom headers in RabbitMQ message properties. It introduces support for the headers field in BasicProperties and updates the Java code to map these headers during message publishing

Examples

import ballerinax/rabbitmq;

rabbitmq:ConnectionConfiguration config = {
    username: "guest",
    password: "guest"
};
rabbitmq:Client rabbitmqClient = check new ("localhost", 5672, config);

public function main() returns error? {
    map<anydata> headers = {"header1": "value1", "header2": "value2"};
    rabbitmq:BasicProperties basicProperties = {headers: headers};
    rabbitmq:AnydataMessage anydataMessage = {routingKey: "test", content: "hello world", properties: basicProperties};
    check rabbitmqClient->publishMessage(anydataMessage);
}

Checklist

• Linked to an issue
• Updated the changelog
• Added tests
• Updated the spec
• Checked native-image compatibility

[CLAassistant]

All committers have signed the CLA.

[aashikam]

Hi @DaAlbrecht ,
LGTM
Could you try to add a test for this?

Build failure: The existing tests seems to have failed? Did you try building this locally?

[DaAlbrecht]

Hi @aashikam

The tests didn't pass because I haven't added support for consuming messages and the corresponding headers. Fixed this now and added a new test.

[tharindu-nw]

Some compiler plugin tests seem to be failing still

[aashikam]

I inspected the error. This comes for the following files but they have correctly used the rabbitmq:AnydataMessage record.

And the PR does not include any compiler plugin related changes.

Fix

Added the fix here DaAlbrecht#1
@DaAlbrecht please merge, or you can add these changes to your PR by yourself. This fixes the compiler plugin test failure.

[DaAlbrecht]

Thank you for the fix! @aashikam merged your pr

[aashikam]

LGTM