* Remove unnecessary type conversions

* Consolidate repeated strings into consts

* Clothe return statements

* Update blockchain/v1/reactor_fsm_test.go

Co-Authored-By: Anton Kaliaev <anton.kalyaev@gmail.com>

This PR repairs linter errors seen when running the following commands:
golangci-lint run --no-config --disable-all=true --enable=unconvert
golangci-lint run --no-config --disable-all=true --enable=goconst
golangci-lint run --no-config --disable-all=true --enable=nakedret

Contributes to #3262

* tm-cmn to tm-db

* go.mod changes

* go.mod changes

* more go.mod

* fix tm-db

* ci fix, pending change

Add gocritic as a linter

    The linting is not complete, but should i complete in this PR or in a following.

    23 files have been touched so it may be better to do in a following PR


Commits:

* Add gocritic to linting

- Added gocritic to linting

Signed-off-by: Marko Baricevic <marbar3778@yahoo.com>

* gocritic

* pr comments

* remove switch in cmdBatch

* implement broadcast_duplicate_vote endpoint

* fix test_cover

* address comments

* address comments

* Update abci/example/kvstore/persistent_kvstore.go

Co-Authored-By: mossid <torecursedivine@gmail.com>

* Update rpc/client/main_test.go

Co-Authored-By: mossid <torecursedivine@gmail.com>

* address comments in progress

* reformat the code

* make linter happy

* make tests pass

* replace BroadcastDuplicateVote with BroadcastEvidence

* fix test

* fix endpoint name

* improve doc

* fix TestBroadcastEvidenceDuplicateVote

* Update rpc/core/evidence.go

Co-Authored-By: Thane Thomson <connect@thanethomson.com>

* add changelog entry

* fix TestBroadcastEvidenceDuplicateVote

* Remove db from tendemrint in favor of tendermint/tm-cmn

- remove db from `libs`
- update dependancy, there have been no breaking changes in the updated deps
	- https://github.com/grpc/grpc-go/releases
	- https://github.com/golang/protobuf/releases

Signed-off-by: Marko Baricevic <marbar3778@yahoo.com>

* changelog add

* gofmt

* more gofmt

* tm-cmn to tm-db

* go.mod changes

* go.mod changes

* more go.mod

* fix tm-db

* ci fix, pending change

Add gocritic as a linter

    The linting is not complete, but should i complete in this PR or in a following.

    23 files have been touched so it may be better to do in a following PR


Commits:

* Add gocritic to linting

- Added gocritic to linting

Signed-off-by: Marko Baricevic <marbar3778@yahoo.com>

* gocritic

* pr comments

* remove switch in cmdBatch

* implement broadcast_duplicate_vote endpoint

* fix test_cover

* address comments

* address comments

* Update abci/example/kvstore/persistent_kvstore.go

Co-Authored-By: mossid <torecursedivine@gmail.com>

* Update rpc/client/main_test.go

Co-Authored-By: mossid <torecursedivine@gmail.com>

* address comments in progress

* reformat the code

* make linter happy

* make tests pass

* replace BroadcastDuplicateVote with BroadcastEvidence

* fix test

* fix endpoint name

* improve doc

* fix TestBroadcastEvidenceDuplicateVote

* Update rpc/core/evidence.go

Co-Authored-By: Thane Thomson <connect@thanethomson.com>

* add changelog entry

* fix TestBroadcastEvidenceDuplicateVote

* Remove db from tendemrint in favor of tendermint/tm-cmn

- remove db from `libs`
- update dependancy, there have been no breaking changes in the updated deps
	- https://github.com/grpc/grpc-go/releases
	- https://github.com/golang/protobuf/releases

Signed-off-by: Marko Baricevic <marbar3778@yahoo.com>

* changelog add

* gofmt

* more gofmt

* abci/example: use base64 for update validator set

* update kvstore/README.md

* update CHANGELOG_PENDING.md and abci/example/kvstore/README.md

* Refactor signature of Application.CheckTx

* Refactor signature of Application.DeliverTx

* Refactor example variable names for clarity and consistency

* Rename method variables for consistency

* Rename method variables for consistency

* add a changelog entry

* update docs

* libs: Remove usage of custom Fmt, in favor of fmt.Sprintf

Closes #2193

* Fix bug that was masked by custom Fmt!

This reverts commit d02c5d1e30.