[pdata] Implement Go 1.23 style iterators

[yurishkuro]

Is your feature request related to a problem? Please describe.

Iterating through pdata structures today is pretty convoluted, e.g.

for i := 0; i < traces.ResourceSpans().Len(); i++ {
	resource := traces.ResourceSpans().At(i)
	for j := 0; j < resource.ScopeSpans().Len(); j++ {
		scope := resource.ScopeSpans().At(j)
		for k := 0; k < scope.Spans().Len(); k++ {
			span := scope.Spans().At(k)

Describe the solution you'd like
Go 1.23 introduced the ability to use iterators for looping through custom structs. The above code could look like this, if we introduce iterator functions to pdata, e.g. Seq() and Seq2():

for resource := range traces.ResourceSpans().Seq() {
	for scope := range resource.ScopeSpans().Seq() {
		for span := range scope.Spans().Seq() {

for i, resource := range traces.ResourceSpans().Seq2() {
	for j, scope := range resource.ScopeSpans().Seq2() {
		for k, span := range scope.Spans().Seq2() {

[bogdandrutu]

@yurishkuro good call, will do when we move to minimum supported version to be 1.23