feat: ability to enable/disable features based on backend version

[theborakompanioni]

Is your feature request related to a problem? Please describe.

With "import wallet" functionality in #621 on its way, there needs to be a way to enable/disable the feature depending on the backend version. Luckily, in the current master of JM, a /getinfo request exists that returns this information.

Describe the solution you'd like

Show some features only with a compatible JM backend version.
e.g. if the /getinfo request does not exists, the backend version less than or equal to v0.9.9, if it exists, make sure the version is greater than or equal to v0.9.10 (or v0.9.10dev).

First usage of this functionality should be the "import wallet" feature, that will exist from v0.9.10 (or 0.9.10dev) on!
If the backend is not compatible, the "import wallet" feature should be disabled and the user should be made aware, that an update would enable it. e.g. disable the button and show a tooltip, or redirect to a dedicated page with more information.

Additional context

This can be worked on after #621 has been merged.