Feature/resource upload size

[Andreass2]

Description

• Global max filetransfer size

• Customizable max size on resource level. if null, it uses the global maximum.

• Added tests for new endpoint

• We previously looked up the resource from the resourceRegistry each time it was needed. Now we store it the first time its used, and then we load it locally, which will probably give a small performance boost.

• I added the global max as an environment variable, meaning we can just create a new replica of a container app in azure to change it. Another solution I considered was to store the value in the database, but discarded it as I think the global max will seldom change.

Related Issue(s)

• Støtte for Konfigurerbar filstørrelsesbegrensing #337

Verification

• Your code builds clean without any errors or warnings
• Manual testing done (required)
• Relevant automated test added (if you find this hard, leave it and we'll help out)
• All tests run green

Documentation

• User documentation is updated with a separate linked PR in altinn-studio-docs. (if applicable)