Branding updates for 2.0

[dennisreimann]

Breaking changes

Public

• Remove deprecated CustomCSSLink and EmbeddedCSS properties from Payment Request, Pull Payment, Point of Sale and Crowdfund. They are replaced by the unified store branding functionality.

Internal

• ...FileId properties (which we use in conjunction with file uploads) are replaced with (relative) URLs, which directly reference the file. This was done to allow retrieval and editing via the API. Closes Branding: Change File IDs to full URL #5953.

[NicolasDorier]

@dennisreimann can you document the breaking changes in the description of this PR?

I will then add it to #5964

[NicolasDorier]

return (await _fileService.GetFileUrl(Context.Request.GetAbsoluteRootUri(), fileId))?.Replace("file://", "");

[NicolasDorier]

1. This PR will not work as intended for people using BTCPAY_ROOTPATH other than / (default).
2. If a reference to a file was made, and then ROOTPATH is changed, all the links will be broken.
3. It is also lacking a test on the migration.

It isn't something that is easy to fix, as in the migrations, there isn't any access to the Request.GetAbsoluteRootUri().

Ideally, the FileService should just provide relative paths (like ~/blahblah/blahblah.png), and we would just save this in LogoUrl and resolve the full path when the page is viewed. But this isn't how the API of FileService works and refactoring it is a can of worms.

There is I think two things we could consider:

1. Keeping the ..FileId and removing the migration. If the FileId is set, the the URL is ignored.
2. Allows the URL to have a special format like fileid:FILE_ID, then resolve it when in the view.

I think 2. is probably better, though the migration is still needed.
For 2., it means that rather than doing <a href="@Model.LogoUrl", you'd need <a href="@UrlResolver.Resolve(Model.LogoUrl)", where UrlResolver is a Scoped Service (you can then just inject the IHttpContextAccessor to get access to the Context.Request.GetAbsoluteRootUri() required to call the FileService)

About the migration: I will check later on if I can't replace it with just a simple postgres query. But a test is needed.

[NicolasDorier]

Rebased

[NicolasDorier]

@dennisreimann

1. I rewrote the test to directly insert into DB legacy data and migrate from that, and test all the properties impacted.
2. I rewrote the migration to be simple SQL queries, so we can remove obsolete properties from our classes, and not fear of memory issues on instances with lot's of stores.
3. Now, cssUrl, logoUrl accept fileid:ID which allow reference to a file id rather than a URL.

Two things I noticed:

1. I noticed that paymentSoundUrl can't be changed through the API. Should we add it in this PR?
2. The crowdfund page doesn't actually use the StoreBranding but the ViewModel does. Can we clean that up?

[dennisreimann]

I noticed that paymentSoundUrl can't be changed through the API. Should we add it in this PR?

Done in c703a4c.

The crowdfund page doesn't actually use the StoreBranding but the ViewModel does. Can we clean that up?

The view uses it here — it gets passed to the LayoutHead partial via the ViewData. I think I initially implemented it like this because the store branding is optional for the layouts and I didn't want to introduce a separate model for it.