Add HTTP service for creating snapshots

[chenbxun]

What this PR does / why we need it:
This PR introduces an HTTP service for creating snapshots.
The service listens on 0.0.0.0 and handles snapshot creation requests. Upon receiving a request, it locates the corresponding image file by the given device ID and calls the image's create_snapshot() interface.

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?