Add SPDX header - Batch 2

[AndyScherzinger]

mostly focussing on static assets

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SUMMARY

• Bad licenses: 0
• Deprecated licenses: 0
• Licenses without file extension: 0
• Missing licenses: 0
• Unused licenses: 0
• Used licenses: AGPL-3.0-or-later, OFL-1.1, LicenseRef-NextcloudTrademarks, Apache-2.0, MIT, LicenseRef-StripeTrademarks, LicenseRef-PayPalTrademarks
• Read errors: 0
• Files with copyright information: 310 / 616
• Files with license information: 310 / 616