Add workflow APIs

[SenuDyl]

Purpose

Implement new APIs to manage workflows. Related to the issue: wso2/product-is#23374

Goals

• Provide a set of APIs for managing workflows.
• Support workflow creation, execution, deletion and association with identity-related operations.

Approach

Workflow API Specification

https://app.swaggerhub.com/apis/SenuriMallikarachchi/Workflow/1.0.0

User stories

Summary of user stories addressed by this change>

Release note

Brief description of the new feature or bug fix as it will appear in the release notes

Documentation

Link(s) to product documentation that addresses the changes of this PR. If no doc impact, enter “N/A” plus brief explanation of why there’s no doc impact

Training

Link to the PR for changes to the training content in https://github.com/wso2/WSO2-Training, if applicable

Certification

Type “Sent” when you have provided new/updated certification questions, plus four answers for each question (correct answer highlighted in bold), based on this change. Certification questions/answers should be sent to [email protected] and NOT pasted in this PR. If there is no impact on certification exams, type “N/A” and explain why.

Marketing

Link to drafts of marketing content that will describe and promote this feature, including product page changes, technical articles, blog posts, videos, etc., if applicable

Automation tests

• Unit tests

  Code coverage information

• Integration tests

  Details about the test cases and coverage

Security checks

• Followed secure coding standards in http://wso2.com/technical-reports/wso2-secure-engineering-guidelines? yes/no
• Ran FindSecurityBugs plugin and verified report? yes/no
• Confirmed that this PR doesn't commit any keys, passwords, tokens, usernames, or other secrets? yes/no

Samples

Provide high-level details about the samples related to this feature

Related PRs

List any other related PRs

Migrations (if applicable)

Describe migration steps and platforms on which migration has been tested

Test environment

List all JDK versions, operating systems, databases, and browser/versions on which this feature/fix was tested

Learning

Describe the research phase and any blog posts, patterns, libraries, or add-ons you used to solve the problem.

[CLAassistant]

Thank you for your submission! We really appreciate it. Like many open source projects, we ask that you sign our Contributor License Agreement before we can accept your contribution.
_{You have signed the CLA already but the status is still pending? Let us recheck it.}