Refactor: create service folder

[petersopko]

following from @roiLeo comment here:

• Folder structure #3068 (comment)

Here's the original comment:

• create a service folder in order to organise all the actions (vuex actions -> service call)

I'd like to ask @roiLeo to provide additional information here if possible, I'm out of my depth with regards to services

[roiLeo]

Let's take the example of user identity (from store),
on fetchIdentity action I would call let's say fetchIdentity method from IdentityService.

  async fetchIdentity({ dispatch }: any, address: string) {
    const { api } = Connector.getInstance()
    try {
      const optionIdentity = await api?.isReady.then((a) =>
        a?.query.identity?.identityOf(address)
      )
      const identity = optionIdentity?.unwrapOr(null)
      if (identity) {
        dispatch('setIdentity', { address, identity })
      }
    } catch (e) {
      consola.error('[FETCH IDENTITY] Unable to get identity', e)
    }
  },

become something like

  [FETCH_USER_IDENTITY]: async ({ commit }, address) => {
    const res = await IdentityService.fetchIdentity(address)
    commit(SET_USER_IDENTITY, res)
  },

services folder is used to make/wrap all api calls.
I find this pattern more readable and easier to maintain.

[vikiival]

Next candidate for refactor:

• NFT Storage is here #3358