Optimize CGrpcServer getters

[PProfizi]

Edit: the actual issue was found to be too many gRPC calls to ResultInfo getters when using a LegacyGrpcServer. The solution found was to add a cache decorator to functions called repeatedly.
We thus went down from 1004 gRPC calls waiting a total of 104s, to 166 gRPC calls waiting a total of 15s.

By looking at the GrpcServer calls, caching the os and version properties also decreases total time from 50s to 15s.

There may be further improvements to be made that I did not see with the simple print(model) command.

NB: I did enforce a limit of 50 for the cache while testing, this is TBD
NB2: the first initiative consisting of improving the description given by the server could still be beneficial.
NB3: all changes related to gate have been made in a different PR server-side

Old:
Summary:

Upon arrival of Fluid results, the ResultInfo.__str__ method was enhanced to also show the locations of each available result as they are dynamic, as well as create a map of qualifier names vs IDs, as well as properly detect the fluid physics type.
This creates a performance deficit of 1200% when in LegacyGrpc (without any actual network delay) due to the number of requests made just when requesting for available results.
The goal of this PR is to revert to the server description of the ResultInfo when in LegacyGrpc to bypass this performance bottleneck, while server-side changes are to be made to:

• add result location to available result descriptions
• add a map of available qualifiers
• correctly show the physics type when fluid
• switch to the server description of the ResultInfo in all cases, potentially with some very minor formatting

[codecov]

Codecov Report

Merging #1284 (9538b91) into master (fced584) will decrease coverage by 1.28%.
Report is 7 commits behind head on master.
The diff coverage is 89.47%.

Additional details and impacted files

@@            Coverage Diff             @@
##           master    #1284      +/-   ##
==========================================
- Coverage   87.45%   86.18%   -1.28%     
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  Files          81       81              
  Lines        9234     9248      +14     
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- Hits         8076     7970     -106     
- Misses       1158     1278     +120