Enable IDE0070: UseSystemHashCode (#15715)
Enable IDE0070: UseSystemHashCode (#15715)

Enable [IDE0070: UseSystemHashCode](https://docs.microsoft.com/dotnet/fundamentals/code-analysis/style-rules/ide0070) as warning.
TravisEz13/PowerShell,PaulHigin/PowerShell,PaulHigin/PowerShell,PaulHigin/PowerShell,JamesWTruher/PowerShell-1,TravisEz13/PowerShell,PaulHigin/PowerShell,daxian-dbw/PowerShell,TravisEz13/PowerShell,daxian-dbw/PowerShell,JamesWTruher/PowerShell-1,JamesWTruher/PowerShell-1,TravisEz13/PowerShell,daxian-dbw/PowerShell,daxian-dbw/PowerShell,JamesWTruher/PowerShell-1