[Feat.] support 'prjquota' for rootfs

[BigVan]

users can specified rootfs usage quota through two ways:

• 'rootfsQuota' in config.json. eg:

           {
             ...
               "rootfsQuota": "10g" ,
             ...
           } 

• passing the label "containerd.io/snapshot/disk_quota" when preparing container layer

What this PR does / why we need it:

Which issue(s) this PR fixes (optional, in fixes #<issue number>(, fixes #<issue_number>, ...) format, will close the issue(s) when PR gets merged):
Fixes #

Please check the following list:

• Does the affected code have corresponding tests, e.g. unit test, E2E test?
• Does this change require a documentation update?
• Does this introduce breaking changes that would require an announcement or bumping the major version?
• Do all new files have an appropriate license header?