Improve strands BBE

[Nadeeshan96]

Description

A brief description of the improvement.

Improve strands BBE: https://ballerina.io/learn/by-example/strands/

Need to state

Unless we explicitly wait for the workers or async functions, there is no guarantee that the Ballerina program will wait till they have completed the execution. So there the only log which surely gets printed is io:println("In function worker");. Others may not get printed if the Ballerina program exits before those statements are executed. If we add wait we can see the other logs also.

Need to remove

An annotation can be used to make a strand run on a separate thread.

because that is deprected.

Related website/documentation area

Add/Uncomment the relevant area label out of the following.

Area/BBEs

Describe the problem(s)

A detailed description of the purpose of this improvement.

Describe your solution(s)

A detailed description of how this improvement will solve the problem described above.

Related issue(s) (optional)

Any related issues such as sub tasks and issues reported in other repositories (e.g., component repositories), similar problems, etc.

Suggested label(s) (optional)

Optional comma-separated list of suggested labels. Non committers can’t assign labels to issues, and thereby, this will help issue creators who are not a committer to suggest possible labels.

Suggested assignee(s) (optional)

Optional comma-separated list of suggested team members who should attend the issue. Non committers can’t assign issues to assignees, and thereby, this will help issue creators who are not a committer to suggest possible assignees.

[anupama-pathirage]

@warunalakshitha / @HindujaB, can we prioritize this and complete it?

[gabilang]

Addressing with the PR ballerina-platform/ballerina-distribution#5288