We've just made the main branch as the default one.

Add app.yml workflow

For testing the linux app build to start with.

Use ghcr.io instead of quay.io for Headlamp's container image

This is for being slightly extra careful in what repository tags trigger
the container image publishing, as we want only version tags to do that.
This way, if we e.g. add a Helm chart tag in the future, an image won't
be created because of that.

Fix some console.error key issues

frontend: Make authchooser's titles translatable

And update the existing locales.

Add a LocaleSelect to AuthChooser

Only install frontend production dependencies when making container

locales/es: Fix two minor typos

Signed-off-by: Mauricio Vásquez <mauricio@kinvolk.io>

So that only the required deps to build are installed before
building the docker image.

frontend: Move some deps out of devDependencies because the
build depends on them.

Some dependency updates caused the snapshot changes.

The sagas type updates seem to have a problem with cancelled().

Fix Electron integration, show lang selector on front page, generate LocaleSelect options from config

Use the locales set in i18n/config@supportedLngs to generate the
menuitems.

Use Browser or OS light/dark theme preference

Change i18n from logical keys to "textual" ones, add app localization, add PT/ES localizations

These changes allow the user to have localization in the desktop
application (menu) and to change it from the Headlamp's frontend.

Also changes the namespace separator key from ":" to "|" to avoid
parsing issues from i18next.