Remove emissions method availability exception from descriptions

[kndehaan]

Context

With the 1990 and start year direct emissions data coming available for regional Dutch datasets, the descriptions in the front-end have been updated to not mention that the emission method is incomplete for those datasets.

Related

Goes with:

• https://github.com/quintel/etdataset/pull/1097
• Direct emissions import of Dutch regional emissions.csv from regional data pipeline etsource#3465
• Remove emissions method availability exception from descriptions #4763

Checklist

• I have tested these changes
• I have updated documentation as needed
• I have tagged the relevant people for review

[jort-wolda]

Had to rebase to master to run locally due to the switch to etlauncher. The new IPCC chart also that was rebased into this branch also had the line about direct emissions not yet being available for regional datasets. I deleted this.

I also noticed that in the en_emissions.yml, it still said the direct emissions method wasn't available for dutch regional datasets for the original direct emissions chart. Maybe this was overlooked or it happened due to the rebase. I deleted it now however.

One more side note, the docs still say: "Complete user output will first be available for national datasets and will later become availbale for regional (Dutch) datasets."

This is not part of this PR but maybe this should also be updated if everything's available for the regional datasets as well now.

[jort-wolda]

Looks good in general, ran into an issue with rebasing to master to run locally. Had to do minor changes because of it. See comment.

Everything's good now

[kndehaan]

Ready for final review by @mabijkerk