by SSShuai1999 @SSShuai1999
Implement PercentageParser.
According to the /^(\+|\-)?(\d*)?(\%)?$/ regularity to match T and get three matches.
The structure should be: [plus or minus, number, unit]
If it is not captured, the default is an empty string.
For example:
type PString1 = ''
type PString2 = '+85%'
type PString3 = '-85%'
type PString4 = '85%'
type PString5 = '85'
type R1 = PercentageParser<PString1> // expected ['', '', '']
type R2 = PercentageParser<PString2> // expected ["+", "85", "%"]
type R3 = PercentageParser<PString3> // expected ["-", "85", "%"]
type R4 = PercentageParser<PString4> // expected ["", "85", "%"]
type R5 = PercentageParser<PString5> // expected ["", "85", ""]
