SetColWidth and SetColVisible, InsertCol is not good performance enough

[hybnew]

the function of SetColWidth and SetColVisible as well as InsertCol will take long time to be done, each of them will cost more 1s , as we can see below in the flame graph.

Steps to reproduce the issue:

1. call function SetColWidth and SetColVisible
2. save excel

Describe the results you received:
the two step will take a long time.

Describe the results you expected:
the two step will not take a long time.

Output of go version:

go version go1.14 darwin/amd64

Excelize version or commit ID:

v2.3.1

Environment details (OS, Microsoft Excel™ version, physical, etc.):
THANKS FOR REVIEW THIS ISSUE.