Enables production data from CSV file and fixes failing probability distribution test

[edubarrosTNO]

Enables production data to be loaded from CSV file and fixes failing probability distribution test

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Contributor checklist

• [x] :tada: This PR partially addresses #382.
• [x] :scroll: I have broken down my PR into the following tasks:
  • [x] Modify parser to allow for new optional entry in the configuration file.
  • [x] Create class CSVData as an alternative to FlowData.
  • [x] Replace production data dataframe loaded from reference simulation by data loaded from CSV file.
  • [x] Fix probability distributions test function (deprecated replacement of NaNs by None)
  • [x] Update documentation and CHANGELOG.md.
  • [x] Change config_parser for new position of observation vectors entry in configuration file.
• [x] :robot: I have added tests, or extended existing tests, to cover any new features or bugs fixed in this PR.
• [x] :book: I have considered adding a new entry in CHANGELOG.md.
• [x] :books: I have considered updating the documentation.

[edubarrosTNO]

Previous CI test failed because configuration files from https://github.com/equinor/flownet-testdata must be updated (new position of observation vectors entry, PR https://github.com/equinor/flownet-testdata/pull/52). Testdata branch has been changed to verify CI before merging

[edubarrosTNO]

Previous CI test failed because configuration files from https://github.com/equinor/flownet-testdata must be updated (new position of observation vectors entry, PR equinor/flownet-testdata#52). Testdata branch has been changed to verify CI before merging

All CI tests have passed when using the branch of https://github.com/equinor/flownet-testdata/pull/52 - that PR can be merged safely. Next commit of this PR #425 reverts CI back to equinor/master branch, see below