[HUDI-9361] Use merger to replace spark ExpressionPayload

[linliu-code]

Change Logs

1. Create a merger class to replace ExpressionPayload

Impact

Existing tests should be sufficient to demonstrate the merger.

Risk level (write none, low medium or high below)

Medium.

Documentation Update

Describe any necessary documentation update if there is any new feature, config, or user-facing change. If not, put "none".

• The config description must be updated if new configs are added or the default value of the configs are changed
• Any new feature or user-facing change requires updating the Hudi website. Please create a Jira ticket, attach the ticket number here and follow the instruction to make changes to the website.

Contributor's checklist

• [ ] Read through contributor's guide
• [ ] Change Logs and Impact were stated clearly
• [ ] Adequate tests were added if applicable
• [ ] CI passed

[hudi-bot]

CI report:

• 499c54159021eda85d52eafaa8fd66c004105907 Azure: FAILURE

Bot commands

@hudi-bot supports the following commands:

• @hudi-bot run azure re-run the last Azure build