ATT&CK: create user

[VakarisZ]

We already have a "create user account" post breach action, but it's not mapped to the ATT&CK matrix.

Let's add this PBA to the matrix as Create Account attack technique.

1. The "Create Account" technique should be present in attack matrix and user should be able to toggle it.
2. On hover a brief with information about this particular attack technique should appear.
3. This technique should be mapped with "Back door user" post breach action. This means that when "Create Account" is turned off, "Back door user" should turn off and vice versa.
4. After exploitation, "Create Account" technique should be present on the ATT&CK report page.

[ShayNehmad]

Important to note @VakarisZ @shreyamalviya - The other PBA also creates a new user and even impersonates as it to perform actions:
https://attack.mitre.org/techniques/T1204/