Generate profiling pdata (open-telemetry#10195)

<!--Ex. Fixing a bug - Describe the bug and how this fixes the issue.
Ex. Adding a feature - Explain what this achieves.-->
#### Description

This generates the pdata for profiles.

<!-- Issue number if applicable -->
#### Link to tracking issue
Last step of open-telemetry#10109.

<!--Describe what testing was performed and which tests were added.-->
#### Testing

The generated code is unit-tested by generated tests.

cc @mx-psi

---------

Co-authored-by: Pablo Baeyens <pbaeyens31+github@gmail.com>
Co-authored-by: Pablo Baeyens <pablo.baeyens@datadoghq.com>

.chloggen/profiles-pdata.yaml

@@ -0,0 +1,25 @@
+# Use this changelog template to create an entry for release notes.
+
+# One of 'breaking', 'deprecation', 'new_component', 'enhancement', 'bug_fix'
+change_type: enhancement
+
+# The name of the component, or a single word describing the area of concern, (e.g. otlpreceiver)
+component: pdata
+
+# A brief description of the change.  Surround your text with quotes ("") if it needs to start with a backtick (`).
+note: Introduce generated experimental pdata for profiling signal.
+
+# One or more tracking issues or pull requests related to the change
+issues: [10195]
+
+# (Optional) One or more lines of additional information to render under the primary note.
+# These lines will be padded with 2 spaces and then inserted directly into the document.
+# Use pipe (|) for multiline entries.
+subtext:
+
+# Optional: The change log or logs in which this entry should be included.
+# e.g. '[user]' or '[user, api]'
+# Include 'user' if the change is relevant to end users.
+# Include 'api' if there is a change to a library API.
+# Default: '[user]'
+change_logs: [api]

pdata/internal/cmd/pdatagen/internal/pprofile_otlp_package.go

@@ -0,0 +1,43 @@
+// Copyright The OpenTelemetry Authors
+// SPDX-License-Identifier: Apache-2.0
+
+package internal // import "go.opentelemetry.io/collector/pdata/internal/cmd/pdatagen/internal"
+import (
+	"path/filepath"
+)
+
+var pprofileotlp = &Package{
+	name: "pprofileotlp",
+	path: filepath.Join("pprofile", "pprofileotlp"),
+	imports: []string{
+		`otlpcollectorprofile "go.opentelemetry.io/collector/pdata/internal/data/protogen/collector/profiles/v1experimental"`,
+	},
+	testImports: []string{
+		`"testing"`,
+		``,
+		`"github.com/stretchr/testify/assert"`,
+	},
+	structs: []baseStruct{
+		exportProfilesPartialSuccess,
+	},
+}
+
+var exportProfilesPartialSuccess = &messageValueStruct{
+	structName:     "ExportPartialSuccess",
+	description:    "// ExportPartialSuccess represents the details of a partially successful export request.",
+	originFullName: "otlpcollectorprofile.ExportProfilesPartialSuccess",
+	fields: []baseField{
+		&primitiveField{
+			fieldName:  "RejectedProfiles",
+			returnType: "int64",
+			defaultVal: `int64(0)`,
+			testVal:    `int64(13)`,
+		},
+		&primitiveField{
+			fieldName:  "ErrorMessage",
+			returnType: "string",
+			defaultVal: `""`,
+			testVal:    `"error message"`,
+		},
+	},
+}