mirror:support one mirror process to back up specified buckets

[dormanze]

Community Contribution License

All community contributions in this pull request are licensed to the project maintainers
under the terms of the Apache 2 license.
By creating this pull request I represent that I have the right to license the
contributions to the project maintainers under the Apache 2 license.

Description

support one mirror process to back up specified buckets

Motivation and Context

Mirror 100 buckets whose names start with test, you need to create 100 mirror processes. After this pr is introduced, only one process is required to mirror specified buckets.

How to test this PR?

mc mirror --include-bucket 'test*' s3 ~/test

Types of changes

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Optimization (provides speedup with no functional changes)
• Breaking change (fix or feature that would cause existing functionality to change)

Checklist:

• Fixes a regression (If yes, please add commit-id or PR # here)
• Unit tests added/updated
• Internal documentation updated
• Create a documentation update request here