Drop `pgpClient` from all `lookupEmail` results

[rrrooommmaaa]

As per this comment:
#3487 (comment)

[rrrooommmaaa]

@tomholub Are we going to retain pgpClient field in lookupEmail() result?

[tomholub]

I don't think we need to keep any place. Just need to check it's not used for anything - I imagine it's not.

[rrrooommmaaa]

it affects setup-render.ts

      } else { // cannot read gmail to find a backup, or this is outlook
        if (keyserverRes.pgpClient === 'flowcrypt') {
          // a key has been created, and the user has used cryptup in the past - this suggest they likely have a backup available, but we cannot fetch it. Enter it manually
          this.displayBlock('step_2b_manual_enter');
          Xss.sanitizePrepend('#step_2b_manual_enter', `<div class="line red">${Lang.setup.cannotLocateBackupPasteManually}<br/><br/></div>`);
        } else if (this.view.orgRules.canCreateKeys()) {
          // has a key registered, key creating allowed on the domain. This may be old key from PKS, let them choose
          this.displayBlock('step_1_easy_or_manual');
        } else {
          // has a key registered, no key creating allowed on the domain
          this.displayBlock('step_2b_manual_enter');
        }
      }
      ```