add collection subscribe support

[shynome]

This pr is based on the last pr generic collection support

simple usage example, don't deal error

package main

import (
	"log"

	"github.com/r--w/pocketbase"
)

func main() {
	client := pocketbase.NewClient("http://localhost:8090")
	collection := pocketbase.CollectionSet[map[string]any](client, "posts_public")

	stream, err := collection.Subscribe()
        defer stream.Unsubscribe()
	err = stream.WaitAuthReady() // This step is required, the subscribe target maybe is error

	for ev := range stream.Events() {
		log.Print(ev.Action, ev.Record)
	}
}

[r--w]

Hi @shynome thats great contribution, can you fix the linter suggestions before I do the review?

[shynome]

This time I ran make check before committing and it fixed the linter suggestion

[r--w]

This closes #7
thank you @shynome, I made some minor changes hope you don't mind

[shynome]

🎉 ( Of course I don't mind Radoslaw Wesolowski ***@***.***> 于 2022年12月12日周一 22:10写道：

…

This closes #7 <https://github.com/r--w/pocketbase/issues/7> thank you @shynome <https://github.com/shynome>, I made some minor changes hope you don't mind — Reply to this email directly, view it on GitHub <https://github.com/r--w/pocketbase/pull/11#issuecomment-1346575521>, or unsubscribe <https://github.com/notifications/unsubscribe-auth/AEEDRS5KNPZSGGPV3NBREALWM4W53ANCNFSM6AAAAAAS3BRVNU> . You are receiving this because you were mentioned.Message ID: ***@***.***>