Too many assets in precache-manifest

[pixtron]

Describe the bug

There are ~930 assets in the precache manifest, most of them are locale files which the user never wont use.

Also all the precaching requests for all assets are executed at the same time. In chrome this leads to blocking subsequent xhr requests (for example login request to /api/v2/tokens)

To Reproduce

Load the app see network inspector.

Expected behavior

Remove assets not necessary.

Environment

• web-client version: 3.2.0
• balloon server version: N/A
• Deployed as: N/A
• client os: N/A
• browser: N/A

Additional context

Probably related to #202