### Description
This pull request removes duplicated code related to MongoDB connection/disconnection attempts. This code was copied across all 8 microservices.
The functionality is now unified under the `common/dbutil` package.
### Description
Tracking issue: https://github.com/wormhole-foundation/wormhole-explorer/issues/377
This pull request modifies the analytics service so that it persists price information for a VAA in MongoDB. Data is stored only for token bridge VAAs, and only if the price is cached for the symbol being used.
A new collection `transferPrices` has been created, with the following document model:
```
{
"_id": "22/0000000000000000000000000000000000000000000000000000000000000001/18087",
"price": "0.999684",
"symbol": "USDC",
"timestamp": 2023-06-06T14:04:47.000+00:00
"tokenAmount": "0.1",
"usdAmount": "0.0999684"
}
```
### Summary
Often times, the analytics service fails to start due to connectivity issues with other services (specifically redis).
Previously, no log information was being emitted, which made it hard to troubleshoot the exact reason for the service failing to start.
This pull request adds log messages when the service starts to make those cases easier to debug.