Ensure History Changes only if Resource Changes

[alexanderkiel]

This change introduces a new trasnaction command called "keep" that just means: "Keep the resource of it is not changed in between." Unlike "put", "keep" will not introduce a new history entry. The command "keep" is always conditional because the detection of no changes will be done outside of the transaction.

Closes: #777

[codecov]

Codecov Report

Merging #1041 (6994522) into develop (3982d14) will increase coverage by 0.07%.
The diff coverage is 99.67%.

Additional details and impacted files

@@             Coverage Diff             @@
##           develop    #1041      +/-   ##
===========================================
+ Coverage    94.40%   94.48%   +0.07%     
===========================================
  Files          243      243              
  Lines        15466    15639     +173     
  Branches       369      368       -1     
===========================================
+ Hits         14601    14776     +175     
+ Misses         496      495       -1     
+ Partials       369      368       -1     

Impacted Files	Coverage Δ
modules/db/src/blaze/db/impl/db.clj	91.54% <0.00%> (ø)
modules/anomaly/src/blaze/anomaly.clj	100.00% <100.00%> (ø)
modules/anomaly/src/blaze/anomaly_spec.clj	100.00% <100.00%> (ø)
modules/async/src/blaze/async/comp.clj	100.00% <100.00%> (ø)
modules/async/src/blaze/async/comp_spec.clj	100.00% <100.00%> (ø)
...assandra/src/blaze/db/resource_store/cassandra.clj	98.00% <100.00%> (ø)
modules/db/src/blaze/db/impl/index/cbor.clj	100.00% <100.00%> (ø)
modules/db/src/blaze/db/impl/index/tx_error.clj	100.00% <100.00%> (ø)
modules/db/src/blaze/db/node.clj	97.99% <100.00%> (+0.06%)	⬆️
modules/db/src/blaze/db/node/transaction.clj	100.00% <100.00%> (ø)
... and 18 more

... and 2 files with indirect coverage changes