Update the Meterpreter config block to use TLVs

[adfoster-r7]

Summary

The current Meterpreter config block doesn't use TLVs, which makes adding fields a backwards incompatible change.

Context:

https://github.com/rapid7/metasploit-framework/blob/30e1930444ee4bdab8743887ef0fdb04ff5a7cec/docs/metasploit-framework.wiki/Meterpreter-Configuration.md#loading-configuration-in-windows-meterpreter

Example change to add logging path information:

https://github.com/rapid7/metasploit-payloads/pull/563/files#diff-384c4e4ec356dff681933fa452e28ea065d62bde3c0b81d26ef15f27db80d885

Not verified: This config block may be marked as being intentionally RWX which can be easily detected.