[MINOR] Avoid listing files for empty tables

[the-other-tim-brown]

Change Logs

• Avoid extra listing when initializing MDT and on first commit with small file handling
• Make listing use a queue instead of copying linked lists in MDT init

Impact

Minor reduction in overhead when initializing MDT

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

None

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:

• 3062782 Azure: CANCELED Azure: SUCCESS

Bot commands

@hudi-bot supports the following commands:

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

[yihua]

Azure CI is green.