improvements and fixes for http requests

- fix for gun worker termination in some circumstances
- pool for http clients (ex_aws, tzdata)
- default pool timeouts for gun
- gun retries on gun_down messages
- s3 upload timeout if streaming enabled

lib/pleroma/http/tzdata.ex

@@ -11,6 +11,8 @@ defmodule Pleroma.HTTP.Tzdata do
 
   @impl true
   def get(url, headers, options) do
+    options = Keyword.put(options, :adapter, pool: :upload)
+
     with {:ok, %Tesla.Env{} = env} <- HTTP.get(url, headers, options) do
       {:ok, {env.status, env.headers, env.body}}
     end
@@ -18,6 +20,8 @@ defmodule Pleroma.HTTP.Tzdata do
 
   @impl true
   def head(url, headers, options) do
+    options = Keyword.put(options, :adapter, pool: :upload)
+
     with {:ok, %Tesla.Env{} = env} <- HTTP.head(url, headers, options) do
       {:ok, {env.status, env.headers}}
     end