User name format in CreateUserActivity

[psp589]

if the user creates a user name with whitespaces at the end or the start this will cause you a lot of problems with physical paths and the virtual ones,because in physicals you can't have whitespaces but in the orchard objects you'll have the paths with the whitespaces (using the user name with the whitespaces to compose the path)

[dnfclas]

Hi @psp589, I'm your friendly neighborhood .NET Foundation Pull Request Bot (You can call me DNFBOT). Thanks for your contribution!

This seems like a small (but important) contribution, so no Contribution License Agreement is required at this point. Real humans will now evaluate your PR.

TTYL, DNFBOT;

[dnfclas]

@psp589, Thanks for signing the contribution license agreement so quickly! Actual humans will now validate the agreement and then evaluate the PR.

Thanks, DNFBOT;

[sebastienros]

Can you please create an issue for this PR so we can track the fix when we release?

[psp589]

The issue was already created #6946