Rename strategy store to sampling strategy provider

[yurishkuro]

Which problem is this PR solving?

• The original naming was confusing, as both static & adaptive implementations were returning, but not storing the sampling strategies. There was also another confusion between "strategy store" (aka provider) and "sampling store" (an actual storage that records throughputs and calculated strategies but only for adaptive sampling).

Description of the changes

• Rename packages, interfaces, methods, and variables
• Move calculationstrategy package inside adaptive as it's not used anywhere else

How was this change tested?

• go run ./cmd/collector and go run ./cmd/all-in-one must compile

[codecov]

Codecov Report

Attention: Patch coverage is 93.65079% with 4 lines in your changes missing coverage. Please review.

Project coverage is 96.21%. Comparing base (082d2e0) to head (252980d).

Files	Patch %	Lines
cmd/collector/app/server/test.go	0.00%	2 Missing ⚠️
cmd/collector/app/collector.go	95.00%	0 Missing and 1 partial ⚠️
...in/sampling/strategyprovider/adaptive/processor.go	83.33%	1 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #5634      +/-   ##
==========================================
+ Coverage   96.19%   96.21%   +0.02%     
==========================================
  Files         327      327              
  Lines       16014    16014              
==========================================
+ Hits        15404    15408       +4     
+ Misses        433      431       -2     
+ Partials      177      175       -2     

Flag	Coverage Δ
badger_v1	8.05% <ø> (ø)
badger_v2	1.93% <ø> (ø)
cassandra-3.x-v1	16.45% <ø> (ø)
cassandra-3.x-v2	1.85% <ø> (ø)
cassandra-4.x-v1	16.45% <ø> (ø)
cassandra-4.x-v2	1.85% <ø> (ø)
elasticsearch-7.x-v1	18.88% <ø> (ø)
elasticsearch-8.x-v1	19.07% <ø> (ø)
elasticsearch-8.x-v2	19.09% <ø> (ø)
grpc_v1	9.47% <ø> (-0.02%)	⬇️
grpc_v2	7.53% <ø> (ø)
kafka	9.77% <ø> (ø)
opensearch-1.x-v1	18.94% <ø> (+0.01%)	⬆️
opensearch-2.x-v1	18.94% <ø> (+0.01%)	⬆️
opensearch-2.x-v2	18.93% <ø> (-0.02%)	⬇️
unittests	94.09% <93.65%> (+0.02%)	⬆️

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