Add i18n and translations

[3zk1m0]

closes #19

[benjamsf]

Need to show different pictures for users in enrollment flow (android/ios/macMtlsInstructions components used by MtlsCreateView, mainly).

We could solve this by doing similar sets of pictures using English UI:s, import them to components and call them depending on the user localization, is this a good way for it?

Maybe for now, but if/when there are more localizations, it gets bit messy?

[benjamsf]

Login flow, user mgmt tools i18n'ed. To do:

• TAK guides
• change localization thing in an appropriate place
• set localization to fi if useragent is Finnish, else English
• iTAK takzip for iUsers

[benjamsf]

Review ready @3zk1m0

• i18n through the app
• hooks/tak/useFetchZipFile now checks if os if iOS from hooks/helpers/getOperatingSystem, which in turn does that by reading user's useragent. In case of iUser, it offers the second file in the tak array, which is always the itak.zip, from the instructions api, eg. https://mtls.accurate-jennet.pvarki.fi/api/v1/instructions/user
• • this is needed by takintegration, which now should offer iTAK-friendly package there.
• i18n's languageDetectors sniffs the user localization
• in footer, there is a dropdown to choose that manually if wanted
• moreover the feedbackform link in footer now points to different forms depending on if language is en or fi (as googleforms do not support localization).

[benjamsf]

As of testing, the download modal appears to grab the package from TAK-RM-API, and gets a success but nothing gets downloaded. Will try and fix it

[benjamsf]

Review ready again: the previous one was just due accidentally removing the actual thing, that makes the client download what is fetched from the API.

[benjamsf]

@3zk1m0 has reviewed this to look OK, but as the pr was started by him he can't review to approve. So I'll be reviewing & approving it for the merge