golangci-lint/CI: Bump versions and introduce new linters

[thrasher-]

PR Description

Bumps golangci-lint/CI Go versions and introduces a few new linters!

Type of change

• New feature (non-breaking change which adds functionality)

How has this been tested

• go test ./... -race
• golangci-lint run

Checklist

• My code follows the style guidelines of this project
• I have performed a self-review of my own code
• I have commented my code, particularly in hard-to-understand areas
• I have made corresponding changes to the documentation and regenerated documentation via the documentation tool
• My changes generate no new warnings
• I have added tests that prove my fix is effective or that my feature works
• New and existing unit tests pass locally and on Github Actions/AppVeyor with my changes
• Any dependent changes have been merged and published in downstream modules

[codecov]

Codecov Report

Merging #798 (f536cc4) into master (5208d21) will decrease coverage by 0.30%.
The diff coverage is 27.33%.

@@            Coverage Diff             @@
##           master     #798      +/-   ##
==========================================
- Coverage   43.68%   43.38%   -0.31%     
==========================================
  Files         311      311              
  Lines       80042    80287     +245     
==========================================
- Hits        34967    34833     -134     
- Misses      39936    40214     +278     
- Partials     5139     5240     +101     

Impacted Files	Coverage Δ
common/file/file.go	65.51% <0.00%> (-0.59%)	⬇️
common/timeperiods/timeperiods.go	100.00% <ø> (ø)
...vider/currencyconverterapi/currencyconverterapi.go	0.00% <0.00%> (ø)
currency/storage.go	29.44% <ø> (+0.07%)	⬆️
engine/engine.go	28.16% <0.00%> (-0.13%)	⬇️
engine/rpcserver.go	30.95% <0.00%> (-0.30%)	⬇️
exchanges/binance/binance_wrapper.go	41.18% <0.00%> (+0.13%)	⬆️
exchanges/bithumb/bithumb.go	56.96% <0.00%> (-0.53%)	⬇️
exchanges/bithumb/bithumb_ws_orderbook.go	23.70% <0.00%> (ø)
exchanges/bitmex/bitmex_wrapper.go	45.43% <ø> (-0.58%)	⬇️
... and 98 more

---

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[shazbert]

This is an awesome update! 🚀 x 100. Just a couple of nits below.

[shazbert]

tested approved. This is a great update! 🚀

[gloriousCode]

Lovely big PR that looks like it wasn't fun to do! Thanks!
My concerns are only len related and only because its type checking after type checking. Not much of a big deal

One extra thing as a favour is that there are a few instances of the following: *int64(time.Millisecond) where the implementation can now be changed from time.Unix(0, ...*int64(time.Millisecond)) to time.UnixMilli(...)
For example, bitfinex_websocket time.Unix(0, int64(element[0].(float64))*int64(time.Millisecond)),

edit: as this is about linters, the linters themselves pass. So I'm happy for you to say "later" and change this to tACK

[gloriousCode]

tACK! Thanks for making those changes + the unixMilli ones too!

[gloriousCode]

tACK changes!

[gloriousCode]

ACK changes

[shazbert]

tACK! 🥇