Implement JobParametersDB

[chaen]

• Does this need to support both MySQL and ElasticSearch DB? --> only ES
• Can we mix job parameters and job attributes in the interface? (perhaps limiting what can be searched/sorted if technically required) --> NO
• Can we drop the older index formats? --> Yes, done already

[fstagni]

Answers:

• A personal opinion, but I would not provide also the MySQL version: ElasticSearch is a pretty good choice for all Job parameters, and the pilot ones (linking here Extract Pilot Parameters from JobParameters #277).
• Some job attributes (e.g. (Minor)Status, few flags) are changing often until a job reaches a final status. This is not what should go in ES.
• The older index format has already been dropped in [8.1] remove old elastic job parameters db DIRAC#7019

[chrisburr]

We just decided that we should probably drop support for writing to the MySQL JobParametersDB in 8.1, will be finalised at the next BiLD.

[arrabito]

In DIRACGrid/DIRAC#76 I've done a very preliminary implementation of the JobParametersDB in OpenSearch.
I wait for the review, before adding new features.

[fstagni]

Hi @arrabito, since the refactoring mentioned in #76 (comment) is done, would you be willing to complete this task? (mind also DIRACGrid/DIRAC#7292)

[arrabito]

I will be glad to complete this task but I will be able to work on it only starting from about mid May.
Is it acceptable for you?