Rendering: add capabilities check (#44470)

* #44449: add feature check to rendering service

* #44449: formatting

* #44449: rename feature -> capability (https://developer.mozilla.org/en-US/docs/Web/API/MediaStreamTrack/getCapabilities, https://developer.mozilla.org/en-US/docs/Web/API/InputDeviceInfo/getCapabilities)

* #44449: refactor

* #44449: remove commented code

* Update pkg/services/rendering/capabilities.go

Co-authored-by: Agnès Toulet <35176601+AgnesToulet@users.noreply.github.com>

* #44449: review fixes

Co-authored-by: Agnès Toulet <35176601+AgnesToulet@users.noreply.github.com>

pkg/services/rendering/capabilities.go

@@ -0,0 +1,55 @@
+package rendering
+
+import (
+	"errors"
+
+	"github.com/Masterminds/semver"
+)
+
+type Capability struct {
+	name             CapabilityName
+	semverConstraint string
+}
+
+type CapabilityName string
+
+const (
+	ScalingDownImages CapabilityName = "ScalingDownImages"
+	FullHeightImages  CapabilityName = "FullHeightImages"
+)
+
+var ErrUnknownCapability = errors.New("unknown capability")
+var ErrInvalidPluginVersion = errors.New("invalid plugin version")
+
+func (rs *RenderingService) HasCapability(capability CapabilityName) (CapabilitySupportRequestResult, error) {
+	if !rs.IsAvailable() {
+		return CapabilitySupportRequestResult{IsSupported: false, SemverConstraint: ""}, ErrRenderUnavailable
+	}
+
+	var semverConstraint string
+	for i := range rs.capabilities {
+		if rs.capabilities[i].name == capability {
+			semverConstraint = rs.capabilities[i].semverConstraint
+			break
+		}
+	}
+
+	if semverConstraint == "" {
+		return CapabilitySupportRequestResult{}, ErrUnknownCapability
+	}
+
+	compiledSemverConstraint, err := semver.NewConstraint(semverConstraint)
+	if err != nil {
+		rs.log.Error("Failed to parse semver constraint", "constraint", semverConstraint, "capability", capability, "error", err.Error())
+		return CapabilitySupportRequestResult{IsSupported: false, SemverConstraint: semverConstraint}, ErrUnknownCapability
+	}
+
+	imageRendererVersion := rs.Version()
+	compiledImageRendererVersion, err := semver.NewVersion(imageRendererVersion)
+	if err != nil {
+		rs.log.Error("Failed to parse plugin version", "version", imageRendererVersion, "error", err.Error())
+		return CapabilitySupportRequestResult{IsSupported: false, SemverConstraint: semverConstraint}, ErrInvalidPluginVersion
+	}
+
+	return CapabilitySupportRequestResult{IsSupported: compiledSemverConstraint.Check(compiledImageRendererVersion), SemverConstraint: semverConstraint}, nil
+}