v3: Add POST methods

[Andre601]

Current methods required to move:
postGuilds

• RequestHandler#postGuilds(JDA, BotBlockAPI) to PostAction#postGuilds(JDA, BotBlockAPI)
• RequestHandler#postGuilds(Long, Integer, BotBlockAPI) to PostAction#postGuilds(Long, Integer, BotBlockAPI)
• RequestHandler#postGuilds(ShardManager, BotBlockAPI) to PostAction#postGuilds(ShardManager, BotBlockAPI)
• RequestHandler#postGuilds(String, Integer, BotBlockAPI) to PostAction#postGuilds(String, Integer, BotBlockAPI)

startAutoPosting (Will be renamed to enableAutoPost)

• RequestHandler#startAutoPosting(JDA, BotBlockAPI) to GetAction#enableAutoPost(JDA, BotBlockAPI)
• RequestHandler#startAutoPosting(Long, Integer, BotBlockAPI) to GetAction#enableAutoPost(Long, Integer, BotBlockAPI)
• RequestHandler#startAutoPosting(ShardManager, BotBlockAPI) to GetAction#enableAutoPost(ShardManager, BotBlockAPI)
• RequestHandler#startAutoPosting(String, Integer, BotBlockAPI) to GetAction#enableAutoPost(String, Integer, BotBlockAPI)

stopAutoPosting (Will be renamed to disableAutoPost)

• RequestHandler#stopAutoPosting() to GetAction#disableAutoPost()

[Andre601]

Finished moving of Post methods.