feat: use local server styles instead of requested

[ShGKme]

☑️ Resolves

Currently Talk Desktop has copy of master server styles used on the Login and then request remote server styles from the connected Nextcloud server.

Problems:

• Talk frontend in the lastest version might not be compatible with old Nextcloud server
• Loading Talk window is slower, waiting for the styles request

Proposal:

• Store all styles locally
• Add an util to get the styles
• To make it compatible with different server versions - store them separately

New indirectly added features:

• All windows no support the dark theme

Drawbacks:

• Custom themes, including primary color and background, are not supported anymore :(

🖼️ Screenshots

🏚️ Before	🏡 After

🚧 Tasks

• Add script to fetch server styles for a specific Server version
  • Copies core styles and files
  • Fetches PHP generated server styles from themes app
  • Adjusts .reuse/dep5 for fetched styles
• During the build, get the styles depending on used Talk version
• Import local styles in app instead of making the request
• Adjust styles a bit

[Antreesy]

Tested with linux package. Feels a lot, but make sense to store the styles locally

[ShGKme]

Note: currently it doesn't support stable29 and below, because it relies on .reuse/dep5 introduced in Nextcloud 30. but we aren't planning to built Talk Desktop with 29 anymore

[ShGKme]

It's only the first stage on updating styles workflow.
Next steps:

• automatically request switch and request required styles on build
• improve fetching script to make it faster and reusable

Merging for now, seems to work. Huge change is only around generated files.