task: updated environment variables in pre/post cd workflow request

[kartik-579]

Description

Updated variables in pre/post cd workflow request -

1. Git Commit Hash
2. Git Source Type
3. Git Source Value
4. CD pipeline Env name
5. CD pipeline Cluster name
6. Sequential pipeline env names
7. Sequential pipeline cluster names

Fixes #2625 #1989

How Has This Been Tested?

Please describe the tests that you ran to verify your changes. Provide instructions so we can reproduce. Please also list any relevant details for your test configuration

• For multi git apps (multiple commit hash and sources)
• For sequential pipelines (multiple env and cluster names for child cd pipelines)
• For cd pipeline's own env and cluster name

Checklist:

• The title of the PR states what changed and the related issues number (used for the release note).
• Does this PR requires documentation updates?
• I've updated documentation as required by this PR.
• I have performed a self-review of my own code.
• I have commented my code, particularly in hard-to-understand areas.
• I have tested it for all user roles.
• I have added all the required unit/api test cases.

Does this PR introduce a user-facing change?