Implement batch jobs-db for SQL

[dazza-codes]

Use the databases [1] library to implement a jobs-db for SQL-DB options

• implement the ABC for jobs-db
• probably OK to dev/test on sqlite
  • https://github.com/encode/databases#quickstart
• allow switching out sqlite for postgis or mysql (databases and driver support required)
  • use poetry optional-extra dependencies, if necessary
  • optional extra are essential for any drivers that build on install against system libs

Review the jobs-db schemas used by https://github.com/AdRoll/batchiepatchie

[1] https://github.com/encode/databases