feat: add prometheus metrics for caches reverting telemetry metrics

[egonspace]

Description

We found that telemetry has serious performance-degradation problem. (1000 tps -> 600 tps on a single node)
This PR reverts telemetry feature and adds prometheus metrics for caches.

closes: #XXXX

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• Targeted PR against correct branch (see CONTRIBUTING.md)
• Linked to Github issue with discussion and accepted design OR link to spec that describes this work.
• Code follows the module structure standards.
• Wrote unit and integration tests
• Updated relevant documentation (docs/) or specification (x/<module>/spec/)
• Added relevant godoc comments.
• Added a relevant changelog entry to the Unreleased section in CHANGELOG.md
• Re-reviewed Files changed in the Github PR explorer
• Review Codecov Report in the comment section below once CI passes

[codecov]

Codecov Report

Merging #184 (83aa427) into v2/develop (1f739c5) will decrease coverage by 31.55%.
The diff coverage is 72.28%.

@@               Coverage Diff               @@
##           v2/develop     #184       +/-   ##
===============================================
- Coverage       54.99%   23.44%   -31.56%     
===============================================
  Files             812      765       -47     
  Lines           51487   125253    +73766     
===============================================
+ Hits            28317    29362     +1045     
- Misses          20211    92040    +71829     
- Partials         2959     3851      +892     

Impacted Files	Coverage Δ
client/grpc/tmservice/query.pb.go	32.27% <ø> (ø)
client/grpc/tmservice/query.pb.gw.go	30.06% <ø> (ø)
client/keys/root.go	100.00% <ø> (ø)
client/keys/utils.go	44.11% <ø> (+5.22%)	⬆️
crypto/armor.go	85.89% <ø> (ø)
crypto/keys/ed25519/ed25519.go	67.34% <ø> (ø)
crypto/keys/multisig/codec.go	100.00% <ø> (ø)
crypto/keys/secp256k1/secp256k1.go	86.79% <ø> (ø)
server/config/toml.go	18.18% <ø> (ø)
simapp/test_helpers.go	8.41% <0.00%> (+7.91%)	⬆️
... and 201 more