We followed the C++ style to register configFactory, but it's not a proper choice for Golang filter.
Here is the Reasons:

1. Golang introduced the ConfigParser interface to Parse/validate a config, configFactory does not need to parse config.
2. better performance. By using fiterFactory, we could ommit generate a closure per http request, that may take ~1ns.

Yep, this is a breaking change, people need to change the register API.
So, I suggest we fix it earlier.

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Key	Value
ref	21c18f44bfa2180da1ee1c9b6d5775461845f877
sha	f0c241f
pr	32183
base-sha	12e928c
actor	@doujiang24
message	golang filter: change register configFactory to filterFactory...
started	1707106355.691536
target-branch	main
trusted	false

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