Convert dump content in logstore/Metablk to base64 encoded format and add Metablk object view

[shosseinimotlagh]

Sample:
python hs_http_cli_tool.py get_object --name=MetaBlkMgr
python hs_http_cli_tool.py cli_tool get_object --type=MetaBlk
python hs_http_cli_tool.py get_object --type=MetaBlk --batch_size=3 --next
python hs_http_cli_tool.py get_object --name=MetaBlk_LogStoreFamily0 --verbosity=2
python hs_http_cli_tool.py get_object --name=MetaBlk_LogStoreFamily0 --verbosity=3

[codecov-commenter]

Codecov Report

Merging #123 (fcf284d) into stable/v3.x (4923483) will decrease coverage by 0.22%.
The diff coverage is 7.92%.

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@@               Coverage Diff               @@
##           stable/v3.x     #123      +/-   ##
===============================================
- Coverage        45.53%   45.31%   -0.22%     
===============================================
  Files              126      126              
  Lines            16268    16360      +92     
  Branches          1924     1943      +19     
===============================================
+ Hits              7408     7414       +6     
- Misses            8155     8237      +82     
- Partials           705      709       +4     

Impacted Files	Coverage Δ
src/api/meta_interface.hpp	100.00% <ø> (ø)
src/engine/common/homestore_utils.cpp	34.04% <0.00%> (-25.22%)	⬇️
src/homeblks/homeblks_http_server.cpp	20.09% <0.00%> (ø)
src/homeblks/volume/volume.hpp	52.94% <ø> (ø)
src/homelogstore/log_store.cpp	35.78% <0.00%> (-1.09%)	⬇️
src/engine/meta/meta_blks_mgr.cpp	25.06% <11.59%> (-1.47%)	⬇️

... and 8 files with indirect coverage changes

[yamingk]

Can we add a new test case to cover this functionality?

[szmyd]

lgtm