Provide progress report on pull operations

[StefanCuypers]

Is your feature request related to a problem? Please describe.
Idea #376

Describe the solution you'd like
Pull requests, espcially initial ones, can take some time, so it would be great if we could inform the user of progress.
This requires a reporting of progress.

Describe alternatives you've considered
I've counted the rows on tables every 5 seconds, but only gives an idea during initial sync and is slowing down synchronization itself due to concurrent database access.

Additional context
The Microsoft DataSyncClient has a SynchronizationProgress event. It would be nice if something similar could be implemented.

[StefanCuypers]

I will be working on this an create a PR once its done.

[StefanCuypers]

I've created an event that reports back. Just need to add tests for this, but I'm having trouble setting up the live test environment.
azd up reports errors. Any idea how to solve that?

ERROR: error executing step command 'provision': initializing provisioning manager: failed to compile bicep template: failed running bicep build: exit code: 1, stdout: , stderr: C:\t\Datasync2\infra\resources.bicep(37,5) : Warning no-unused-vars: Variable "mongoaciServerName" is declared but never used. [https://aka.ms/bicep/linter/no-unused-vars]
C:\t\Datasync2\infra\main.bicep(54,62) : Error BCP083: The type "outputs" does not contain property "MONGOACI_CONNECTIONSTRING". Did you mean "COSMOS_CONNECTIONSTRING"? [https://aka.ms/bicep/core-diagnostics#BCP083]
C:\t\Datasync2\infra\main.bicep(55,59) : Error BCP083: The type "outputs" does not contain property "MYSQL_CONNECTIONSTRING". Did you mean "AZSQL_CONNECTIONSTRING"? [https://aka.ms/bicep/core-diagnostics#BCP083]
C:\t\Datasync2\infra\main.bicep(56,59) : Error BCP083: The type "outputs" does not contain property "PGSQL_CONNECTIONSTRING". Did you mean "AZSQL_CONNECTIONSTRING"? [https://aka.ms/bicep/core-diagnostics#BCP083]

[adrianhall]

Use the TestContainers environment instead for tests.

[StefanCuypers]

I've created pull request #387