PM-1897 prisma middleware for audit fields

[vas3a]

https://topcoder.atlassian.net/browse/PM-1894 - prisma middleware to automatically set updated by & created by based on request context.

• had to drop "not null" from all createdBy & updatedBy columns so we can call .create() and .update() without those params.
• modified the tokenRole guard and moved jwt check to tokenRequestValidator.middleware. This way the user is attached to request early and can be used in the request context.

[jmgasper]

I think this looks good - we shouldn't have to rebuild the database, correct? That's pretty time consuming, since we have to import all legacy data.

[vas3a]

I only worked on the current schema. No updates to the prisma schema were produced. So, there shouldn't be necessary any database rebuild either.