Update mapped task UX

[bbovenzi]

• Disable Run button if not using k8s or celery executors. The UI already knows this info, why not save people the time?
• Add XCom button to Task Instance side panel and modal
• Update Mapped Task table icons to match the icons we already use throughout the app
• Hide or disable task actions that are not available yet for individual mapped tasks

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In case of fundamental code change, Airflow Improvement Proposal (AIP) is needed.
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[github-actions]

The PR is likely OK to be merged with just subset of tests for default Python and Database versions without running the full matrix of tests, because it does not modify the core of Airflow. If the committers decide that the full tests matrix is needed, they will add the label 'full tests needed'. Then you should rebase to the latest main or amend the last commit of the PR, and push it with --force-with-lease.