Adjusts builder extension methods to be friendlier

[rossgrambo]

Preview now with app insights telemetry looks like this:

// Add App Insights
builder.Services.AddApplicationInsightsTelemetry(); // Shouldn't be done by us

builder.Services.AddHttpContextAccessor();

// Add FeatureManagement's TargetingTelemetryInitializer
builder.Services.AddSingleton<ITelemetryInitializer, TargetingTelemetryInitializer>();

// Add FeatureManagement
builder.Services.AddFeatureManagement()
    .WithTargeting() // Uses DefaultHttpTargetingAccessor, requires HttpContextAccessor
    .AddApplicationInsightsTelemetryPublisher();

var app = builder.Build();

//...

app.UseMiddleware<TargetingHttpContextMiddleware>();

Making a few opinionated changes- we can make it:

// Add App Insights
builder.Services.AddApplicationInsightsTelemetry(); // Shouldn't be done by us

builder.Services.AddFeatureManagement()
    .WithTargeting() // Uses DefaultHttpTargetingAccessor, adds HttpContextAccessor if it's not added already
    .AddApplicationInsightsTelemetry(); // Adds TargetingTelemetryInitializer as well

var app = builder.Build();

app.UseMiddleware<TargetingHttpContextMiddleware>();

[rossgrambo]

Telemetry Publisher vs Initializer relationship:

• AddApplicationInsightsTelemetryPublisher publishes Impression events and doesn't directly require the Initializer.
• The Initializer makes all outgoing Telemetry able to be connected to Impression events (by appending TargetingId).

I think it's okay to add these together- because it's very unlikely someone will want the publisher and not want the initializer.

[jimmyca15]

I see three improvements here

(1) Add httpcontext accessor in WithTargeting (2) Add telemetry initializer when adding telemetry publisher (3) Add syntax sugar helper for middleware

(1) Agree to have it. The default targeting context accessor doesn't make sense without http context accessor being present. (2) Agree to have it. The scenario for feature management telemetry is to emit targeting id if present. (3) Doesn't seem helpful enough to me at this point to have it.

[rossgrambo]

Adjusted name of adding App Insights and removed middleware helper. Adjusted PR description to reflect the latest.

.AddApplicationInsightsTelemetry~Publisher~(); ~app.UseFeatureManagement();~