FIX: [bybit][kucoin] fix negative volume, price precision

[bailantaotao]

The precision should be positive. Bybit is according to Kucoin, so it is also incorrect..

Other exchanges are correct.

bybit document: https://bybit-exchange.github.io/docs/v5/market/instrument

              "basePrecision": "0.000001",
                "quotePrecision": "0.00000001",

kucoin document: https://www.kucoin.com/docs/rest/spot-trading/market-data/get-symbols-list

    "quoteIncrement": "0.000001",
    "priceIncrement": "0.000001",

[bbgokarma-bot]

Welcome back! @bailantaotao, This pull request may get 216 BBG.

[bbgokarma-bot]

Re-estimated karma: this pull request may get 223 BBG

[codecov]

Codecov Report

Merging #1372 (ba7e26c) into main (c4f1af0) will not change coverage.
The diff coverage is 100.00%.

@@           Coverage Diff           @@
##             main    #1372   +/-   ##
=======================================
  Coverage   20.99%   20.99%           
=======================================
  Files         568      568           
  Lines       40623    40623           
=======================================
  Hits         8529     8529           
  Misses      31463    31463           
  Partials      631      631           

Files	Coverage Δ
pkg/exchange/bybit/convert.go	76.38% <100.00%> (ø)

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[bailantaotao]

Since the test with -dnum flag caused a precision problem, for example:

a := -int(math.Log10(fixedpoint.NewFromFloat(0.000001).Float64()))
b := -int(math.Log10(fixedpoint.NewFromFloat(0.00000001).Float64()))
t.Log(a, b)
// 6, 7

But b must be 8.

After discussing with @c9s , we can solve it by using NumFractionalDigits.

[bbgokarma-bot]

Hi @bailantaotao,

Well done! 238 BBG has been sent to your polygon wallet. Please check the following tx:

https://polygonscan.com/tx/0xc6b239eca101acae8e5cfeb4f4298211bb036879df3dbaf75a2f441e1f949558

Thank you for your contribution!