Merged PR 59153: Modify log output to indicate sync process more clearly

## What's being changed

The log output for the recently refactored syncs is being adjusted to make it a little bit quieter, and hopefully a little easier to parse and identify the different stages.

Log output for a 2-website sync would now look like this:
```
[2024-10-21T11:42:39.108438+00:00] dotdigital.INFO: Order sync: syncing website 1 [] []
[2024-10-21T11:42:43.052070+00:00] dotdigital.INFO: Order sync: 41 orders processed, 36 selected [] []
[2024-10-21T11:42:43.636881+00:00] dotdigital.INFO: Import id abc pushed to Dotdigital [] []
[2024-10-21T11:42:43.740471+00:00] dotdigital.INFO: 36 orders records batched for website id 1 [] []
[2024-10-21T11:42:44.223513+00:00] dotdigital.INFO: Order sync: syncing website 2 [] []
[2024-10-21T11:42:46.084873+00:00] dotdigital.INFO: Order sync: 50 orders processed, 47 selected [] []
[2024-10-21T11:42:46.409978+00:00] dotdigital.INFO: Order sync: 4 orders processed, 4 selected [] []
[2024-10-21T11:42:47.677370+00:00] dotdigital.INFO: Import id xyz pushed to Dotdigital [] []
[2024-10-21T11:42:47.714536+00:00] dotdigital.INFO: 51 orders records batched for website id 2 [] []
[2024-10-21T11:42:47.813894+00:00] dotdigital.INFO: ----------- Order sync ----------- : 00:00:08, Total processed = 95, Total synced = 87 [] []
```

## Why it's being changed

The big 'title' log lines like:
```
dotdigital.INFO: ----------- Order sync ----------- :
```
should I think only be for a final _summary_ of the relevant sync.

## How to review / test this change

- Reset your customers, subscribers, guests and orders
- Set cron to run
- Observe the log output

Related work items: #273626

Model/Sync/Customer.php

@@ -200,7 +200,7 @@ private function loopByWebsite(WebsiteInterface $website, int $megaBatchSize, in
             if ($loopStart) {
                 $this->logger->info(
                     sprintf(
-                        '----------- %s sync ----------- : Website %d',
+                        '%s sync: syncing website %d',
                         Importer::IMPORT_TYPE_CUSTOMER,
                         $website->getId()
                     )
@@ -234,7 +234,7 @@ private function loopByWebsite(WebsiteInterface $website, int $megaBatchSize, in
                 $offset = 0;
             }
         } while (!$breakValue || $this->totalCustomersSyncedCount < $breakValue);
-        
+
         $this->megaBatchProcessorFactory->create()
             ->process(
                 $megaBatch,

Model/Sync/Guest.php

@@ -192,7 +192,7 @@ private function loopByWebsite(Website $website, int $megaBatchSize, int $breakV
             if ($loopStart) {
                 $this->logger->info(
                     sprintf(
-                        '----------- %s sync ----------- : Website %d',
+                        '%s sync: syncing website %d',
                         Importer::IMPORT_TYPE_GUEST,
                         $website->getId()
                     )

Model/Sync/Order.php

@@ -184,7 +184,7 @@ private function processWebsiteOrders(WebsiteInterface $website)
 
             if ($loopStart) {
                 $this->logger->info(
-                    sprintf('----------- Order sync ----------- : Website %d', $website->getId())
+                    sprintf('Order sync: syncing website %d', $website->getId())
                 );
                 $loopStart = false;
             }

Model/Sync/Subscriber.php

@@ -356,7 +356,7 @@ private function exportAndBatch(
         if ($this->$loopStart) {
             $this->logger->info(
                 sprintf(
-                    '----------- %s sync ----------- : Website %d',
+                    '%s sync: syncing website %d',
                     $prettyCohortName,
                     $website->getId()
                 )