Set-NextcloudUser

[Skons]

With Set-NextcloudUser there are two issues:

1. The password variable should not be a string, when the password parameter can be plaintext it could be exposed in logfiles which could compromise that user. Securestring should be used instead.
2. Some parameters are not to be used together, in my opinion Disable should not be used with any other parameter. This could be easily solved with parametersets: https://devblogs.microsoft.com/powershell/powershell-v2-parametersets/