feat: add option to allow user format the version from path in grape

[xuan-cao-swi]

Description

Based on issue #1431: when a Grape API has multiple versions (for example:

class V5 < Grape::API
  version 'v5', 'v6', 'v7', using: :path

  get '/other' do
    # ...
  end
end

—although using multiple versions in this way is not best practice and may be rare), the route string can become /api/[\"v5\", \"v6\", \"v7\"]//other, which, as the user points out, is not well formatted (see attributes).

attributes=
  {"http.request.method"=>"GET",
   "server.address"=>"localhost:3000",
   "url.scheme"=>"http",
   "url.path"=>"/api/v5/other",
   "user_agent.original"=>"curl/7.74.0",
   "sw.is_entry_span"=>true,
   "code.namespace"=>"V5",
   "http.route"=>"/api/[\"v5\", \"v6\", \"v7\"]//other",
   "http.response.status_code"=>200}

This PR adds a configuration option that allows users to format the version string as they prefer. For example, to produce /api/{v5|v6|v7}/other, a user can provide a lambda like:

OpenTelemetry::SDK.configure do |c|
  c.use 'OpenTelemetry::Instrumentation::Grape',
    {
      version_format: ->(version) {
        version.is_a?(Array) ? "{#{version.join('|')}}" : version.to_s
      }
    }
end

If the user does not provide a config option, the instrumentation keeps the original formatting (for example: "/api/[\"v5\", \"v6\", \"v7\"]//other").

[ericmustin]

@muripic Would you have any time to take a look at this? I believe you contributed the Graph instrumentation (albeit, many years ago), your input would be super helpful.

At a high level I think we'd prefer to solve this within the instrumentation code itself rather than need to support another config option like a callable.