[raft] Pass down locality

[MariemBaccari]

Chained PR: #1627 -> #1642 -> #1643 -> #1644 -> #1645 -> #1646 -> #1649 -> #1650 -> #1651 -> #1653 -> #1654 -> #1656 -> #1657 -> #1655 -> #1666 -> #1667 -> #1668 -> #1669

Pass down locality through consensus (needed for rid operations) mirroring the timestamp middleware.

[mickmis]

LGTM modulo naming suggestion.
PS: this could be applied too to the timestamp package too.

[mickmis]

About naming in this file: it is go-idiomatic to drop the package name from the entities contained in the package. In addition I suggest following doc of context.Value out of consistency. E.g. here:

• type key struct {}
• FromContext(ctx context.Context) (string, error or bool) {}
• MustFromContext(ctx context.Context) string {}
• NewContext(ctx context.Context, locality string) context.Context {}
• Middleware(locality string) func(...) ... {}

[mickmis]

LGTM modulo naming suggestion.
PS: this could be applied too to the timestamp package too.

[MariemBaccari]

@mickmis I opened #1668 to address the naming comment for both timestamp and locality at the same time.

[mickmis]

Note: ignored CI failure, which was flakyness (PR on top of this one succeeded).