Misc. issues with output of interface stub generation

While working on updating FSAC to .net 7, some of our tests around interface stub generation started to fail, I think in part due to the new GetSetMember concept.

Specifically, the following scenario:

```fsharp
type IPrinter =
abstract member Indentation: int with get, set

type Printer() =
interface IPrinter with
member _.Indentation with get () = 42
```

When generated with the 'verbose' mode, the output seems to be ok:

```fsharp
type IPrinter =
abstract member Indentation: int with get, set
type Printer() =
interface IPrinter with
member _.Indentation with get () = 42
member _.Indentation
with set (v: int): unit =
failwith "-"
```

But when generated with the 'non verbose' mode, the output has two problems:

a) the setter line contains type annotations, and
b) the method body isn't indented on the following line

```fsharp
type IPrinter =
abstract member Indentation: int with get, set

type Printer() =
interface IPrinter with
member _.Indentation with get () = 42
member _.Indentation
with set (v: int): unit = // note the annotations on this line
failwith "-" // note the need for one more indentation level
```

The type annotations seem to come from [this line](https://github.com/dotnet/fsharp/blob/main/src/Compiler/Service/ServiceInterfaceStubGenerator.fs#L461), which should check the verbosity.
The lack of indentation seems to come from an interaction with [writeImplementation](https://github.com/dotnet/fsharp/blob/main/src/Compiler/Service/ServiceInterfaceStubGenerator.fs#L382) - when verbosity is off there's an assumption that the body is emitted on the same line, but the use of `WriteLine` for the `with set v =` line prior breaks that assumption. Perhaps the setter-writing portion of the stub needs to indent one more level before calling `writeIndentation`?