Add secret data source boilerplate

Add initial boilerplate code for the "secret"
data source. Currently this code does nothing, the
relevant functionality will be added in later
changes.

internal/datasources/secret/data_source.go

@@ -0,0 +1,72 @@
+// (C) Copyright 2024 Hewlett Packard Enterprise Development LP
+
+//go:build experimental
+
+package secret
+
+import (
+	"context"
+
+	"github.com/HewlettPackard/hpegl-pcbe-terraform-resources/internal/client"
+	"github.com/hashicorp/terraform-plugin-framework/datasource"
+	"github.com/hashicorp/terraform-plugin-log/tflog"
+)
+
+// Ensure provider defined types fully satisfy framework interfaces.
+var _ datasource.DataSource = &DataSource{}
+
+func NewDataSource() datasource.DataSource {
+	return &DataSource{}
+}
+
+// DataSource defines the data source implementation.
+type DataSource struct {
+	client *client.PCBeClient
+}
+
+func (s *DataSource) Metadata(
+	ctx context.Context,
+	req datasource.MetadataRequest,
+	resp *datasource.MetadataResponse,
+) {
+	resp.TypeName = req.ProviderTypeName + "_secret"
+}
+
+func (s *DataSource) Schema(
+	ctx context.Context,
+	req datasource.SchemaRequest,
+	resp *datasource.SchemaResponse,
+) {
+	resp.Schema = SecretDataSourceSchema(ctx)
+}
+
+func (s *DataSource) Configure(
+	ctx context.Context,
+	req datasource.ConfigureRequest,
+	resp *datasource.ConfigureResponse,
+) {
+	// Prevent panic if the provider has not been configured.
+	if req.ProviderData == nil {
+		tflog.Warn(ctx, "provider has not been configured.")
+
+		return
+	}
+
+	s.client = req.ProviderData.(*client.PCBeClient)
+}
+
+func (s *DataSource) Read(
+	ctx context.Context,
+	req datasource.ReadRequest,
+	resp *datasource.ReadResponse,
+) {
+	var data SecretModel
+
+	resp.Diagnostics.Append(req.Config.Get(ctx, &data)...)
+
+	if resp.Diagnostics.HasError() {
+		return
+	}
+
+	resp.Diagnostics.Append(resp.State.Set(ctx, &data)...)
+}