Ship CSV rules and allow to load CSV rule from common path

[Thaodan]

I noticed that some of the CSV rules look quite functional by default for a supported banks.

I was thinking that it could make sense to ship those with hledger-cli and load from a common path i.e. program or data directory and then user data directory.

[simonmichael]

I like the idea in general, though it sounds hard to provide good coverage when you think of all the banks in the world.

It's related to setup, and perhaps could tie in to the https://hledger.org/dev/hledger.html#setup command.

And these require thinking about file layout/locations, and possibly a bit of i18n/l10n.

[simonmichael]

Also related: #507, smarter/automatic CSV conversion