related #4426

not critical but some browsers might have problems

so we don't have to decode/decrypt/encode/encrypt so many times

New concept "simple auth" - authentication that happens immediately (in one http request) without redirecting to any third party.

uppyAuthToken initially used to simply contain an encrypted & json encoded OAuth2 access_token for a specific provider. Then we added refresh tokens as well inside uppyAuthToken #4448. Now we also allow storing other state or parameters needed for that specific provider, like username, password, host name, webdav URL etc... This is needed for providers like webdav, ftp etc, where the user needs to give some more input data while authenticating

Companion:
- `providerTokens` has been renamed to `providerUserSession` because it now includes not only tokens, but a user's session with a provider.

Companion `Provider` class:
- New `hasSimpleAuth` static boolean property - whether this provider uses simple auth
- uppyAuthToken expiry default 24hr again for providers that don't support refresh tokens
- make uppyAuthToken expiry configurable per provider - new `authStateExpiry` static property (defaults to 24hr)
- new static property `grantDynamicToUserSession`, allows providers to specify which state from Grant `dynamic` to include into the provider's `providerUserSession`.

also for thumbnails
for consistency

it wasn't returning the status code (like `got` does on error)
it's needed to respond properly with a http error

instead log error and show the key
this in on par with other i18n frameworks

and don't replace the whole view with a loader when plugin state loading
it will cause auth views to lose state
an inter-view loading text looks much more graceful and is how SearchProviderView works too

add support for passing objects and messages from companion to uppy
this allows companion to for example give a more detailed error when authenticating

don't force the user to use html form
and use preact for it, for flexibility

heavily based on owncloud#1
but modified to work with the new provider user sessions

# Conflicts:
#	packages/@uppy/companion/src/server/controllers/refresh-token.js
#	packages/@uppy/companion/src/server/provider/index.js

this is useful because:

      // onedrive gives some errors here that the user might want to know about
      // e.g. these happen if you try to login to a users in an organization,
      // without an Office365 licence or OneDrive account setup completed
      // 400: Tenant does not have a SPO license
      // 403: You do not have access to create this personal site or you do not have a valid license

# Conflicts:
#	yarn.lock

so that local webdav servers work

# Conflicts:
#	packages/@uppy/companion-client/src/Provider.js
#	packages/@uppy/companion/src/server/provider/error.d.ts

# Conflicts:
#	private/dev/Dashboard.js
#	yarn.lock

(cherry picked from commit 4be2b6f)

Co-authored-by: Antoine du Hamel <antoine@transloadit.com>

see discussion here: #4619 (comment)

Co-authored-by: Antoine du Hamel <antoine@transloadit.com>