[FFL-1318] Add OpenFeature component

[Strech]

What does this PR do?

Adds a new component Datadog::OpenFeature that will give customers an opportunity to use Datadog::OpenFeature::Provider in their open feature SDK.

Motivation:

A Feature Flag Evaluation product we want to pilot.

Change log entry

Yes. TBD

Additional Notes:

This is a draft to work on, don't merge now.

How to test the change?

There will be unit tests added and also new system tests

[github-actions]

Typing analysis

Note: Ignored files are excluded from the next sections.

Untyped methods

This PR introduces 1 untyped method and 2 partially typed methods. It increases the percentage of typed methods from 51.66% to 52.43% (+0.77%).

Untyped methods (+1-0)

❌ Introduced:

sig/datadog/open_feature/provider.rbs:8
└── def initialize: () -> void

Partially typed methods (+2-0)

❌ Introduced:

sig/datadog/open_feature/binding/evaluator.rbs:41
└── def generate: (::Symbol expected_type) -> untyped
sig/datadog/open_feature/configuration/settings.rbs:12
└── def self.add_settings!: (untyped base) -> void

Untyped other declarations

This PR introduces 3 untyped other declarations. It increases the percentage of typed other declarations from 65.76% to 66.3% (+0.54%).

Untyped other declarations (+3-0)

❌ Introduced:

sig/datadog/open_feature/binding/evaluator.rbs:5
└── attr_reader value: untyped
sig/datadog/open_feature/binding/evaluator.rbs:9
└── attr_reader variant: untyped
sig/datadog/open_feature/binding/evaluator.rbs:15
└── attr_reader flag_metadata: untyped

If you believe a method or an attribute is rightfully untyped or partially typed, you can add # untyped:accept to the end of the line to remove it from the stats.

[pr-commenter]

Benchmarks

Benchmark execution time: 2025-11-07 14:47:52

Comparing candidate commit 9cd236e in PR branch add-openfeature-component with baseline commit 333959d in branch master.

Found 0 performance improvements and 1 performance regressions! Performance is the same for 43 metrics, 2 unstable metrics.

scenario:profiling - sample timeline=false

• 🟥 throughput [-0.420op/s; -0.372op/s] or [-5.960%; -5.269%]