Add blob-run-mode for downgrading Titan (#11)

* Add blob-run-mode for downgrading Titan

* fix format issue

* address comment

* change string req to kabab-case

* address comments

* address comments

* fix bug from merge

* address comments

* address comments

* address comments

* address comment

* address comment

* pick comments from mutex-fix

* remove mutex fix

* fix mutex issue in blob storage