EF Core major guard: the message and banners misstate NU1608, the successor and the version #74

Problem

The text that ships with the EF Core major guard (#55, PR #62) misstates three things. All of it is new in 5.5.0, so it is cheapest to correct before the tag; after it, the exception message and the packed READMEs are frozen on nuget.org for the life of the line.

1. NU1608. The exception, the guard's remarks, the four 5.5.0 changelog entries and EfCoreVersionGuardTests say a direct EF Core 11 reference overrides the [10.0.0, 11.0.0) range "with warning NU1608", and the root changelog tells users that NU1608 in their restore output is the sign. During the EF Core 11 release candidates there is no warning at all: 11.0.0-rc.2 sorts below 11.0.0, so it is inside the range. Measured with SDK 11.0.100-rc.2: a net11.0 project referencing EFCore.ComplexIndexes.PostgreSQL 5.4.1 and Npgsql.EntityFrameworkCore.PostgreSQL 11.0.0-rc.2 restores EF Core 11.0.0-rc.2 with no NU1608 and no warning. NU1608 appears only for a GA EF Core 11.
2. The README banner (root and all three packed READMEs) reads "Use CodoMetis.EFCore.SchemaKit, the successor to this package, which serves EF Core 10 only", where the relative clause attaches to SchemaKit: it says the successor serves EF Core 10 only. It also names a package that has no release on nuget.org when 5.5.0 ships, with no pointer to where it is tracked; the exception message does the same.
3. The version in the message is {Major}.{Minor} of the assembly version, whose minor is always 0 for EF Core (11.0.0.0 for every 11.x), so it would say "EF Core 11.0" on an 11.1.

Fix

• Message and docs: an EF Core 11 prerelease is inside the range; a release overrides it with only NU1608. Name the major alone. Point to the SchemaKit tracking issue (Epic: CodoMetis.EFCore.SchemaKit 11.0.0 — the EF Core 11 successor #37) until it has a release.
• Banner: one sentence about this package, one about its successor.

Found in the 5.5.0 pre-tag review (code review of #62, consumer probe on EF Core 11 rc.2).