Improve translation key consistency

[tobyzerner]

We need to solidify our strategy for naming translation keys, and apply it globally for consistency. Initial discussion took place here: http://discuss.flarum.org/d/336-potential-l10n-stumbling-blocks/10

The basic idea is to have context-related suffixes for similar translations (see stumbling block 4) and prefixes to group related translations (stumbling block 5). However, this strategy needs further refinement, and then needs to be applied.

What needs to be done:

• Go through all components in js/forum/src/components, looking for instances of app.trans, cross-matching the keys with their translations in locale/en.yml. Rename keys where necessary so that they are consistent and descriptive.
• Through this process, come up with a brief list of rules/guidelines to follow when naming translation keys.
• Apply the strategy to default extension translations too.

[tobyzerner]

@dcsjapan you might be interested in tackling this :)

[dcsjapan]

I'd be happy to ... give me a while to wrap up the aftermath of my translation job and I'll get right on it.

[dcsjapan]

Okay, I plan to get started on this soonish.

Do you need me to keep a log of key name changes? Any preferences regarding format of the log?

(Come to think of it, I suppose such a log might be of use to the translators, too...)

[tobyzerner]

Yes a log would probably be helpful :) Thanks!

[dcsjapan]

Just adding a mention here for completeness' sake:

#536

This more or less takes care of the first bullet point in the OP.

Prerequisites for using the changes are noted in the PR description!