Wip: support use cache only to run image

[zyfjeff]

Relevant Issue (if applicable)

#1415

Details

Add --blob-cache-path arg to generate raw blobcache file

[codecov]

Codecov Report

Merging #1416 (f57777a) into master (1d93f12) will decrease coverage by 0.03%.
The diff coverage is 24.00%.

@@            Coverage Diff             @@
##           master    #1416      +/-   ##
==========================================
- Coverage   46.44%   46.41%   -0.03%     
==========================================
  Files         123      123              
  Lines       38643    38693      +50     
  Branches    38643    38693      +50     
==========================================
+ Hits        17948    17960      +12     
- Misses      19721    19759      +38     
  Partials      974      974              

Files Changed	Coverage Δ
builder/src/compact.rs	0.00% <0.00%> (ø)
builder/src/core/node.rs	40.90% <0.00%> (-0.85%)	⬇️
builder/src/lib.rs	53.01% <ø> (ø)
builder/src/stargz.rs	0.00% <0.00%> (ø)
src/bin/nydus-image/main.rs	41.32% <25.00%> (-0.31%)	⬇️
builder/src/core/context.rs	47.96% <50.00%> (+0.01%)	⬆️
builder/src/tarball.rs	62.98% <100.00%> (+0.14%)	⬆️