add validation button to Validation page

add info to summary screen
expand and refactor quality calculation

activated when status is set to stored
quality threshold values read from Configuration

adding status_code check
refactor to prevent double code

"suspended" and "discarded" tasks should not be included in the corresponding "Plots" and "Summary" lists, and should not block the validation

(because summary.logs appear multiple times)

replaced fake data tests with real functionality

changed summary layout
bugfix in ratio

To make ATDB being able to be deployed behind a proxy on different address
direct links to address have to be converted in local urls

To deploy on a different url also an environment variable should be set.
Such environment variable is called ATDB_PATH.
For instance if you want to deploy ATDB on https://sdc.astron.nl/asw/atdb
you have to define the environment as ATDB_PATH='/asw/'.