Deprecated Get connections from ConnectionManager

[pc3b3r]

Issue Description

Related to #7839. It's deprecating get connections without a specific reason.

We are creating multiple connections at runtime and after a while we must iterate over all connections, without having a reference to all of them so it's really needed.

As a plus Object.values(<Map>) returns always an empty array

typeorm/src/connection/ConnectionManager.ts

Line 17 in f7eb46d

return Array.from(Object.values(this.connectionMap));

Expected Behavior

ConnectionManager.connections should return the list of active connections

Actual Behavior

Returns an empty array

Steps to Reproduce

await createConnections(connections)
console.log(getConnectionManager().connections)

Are you willing to resolve this issue by submitting a Pull Request?

• ✅ Yes, I have the time, and I know how to start.
• ✖️ Yes, I have the time, but I don't know how to start. I would need guidance.
• ✖️ No, I don’t have the time, but I can support (using donations) development.
• ✖️ No, I don’t have the time and I’m okay to wait for the community / maintainers to resolve this issue.

[imnotjames]

The entirety of the connection manager is deprecated. As such, having a location where there's a central repository of connections in a list is deprecated.

I'll merge this in and make it clearer in a more in depth deprecation message.

[pleerock]

@imnotjames created #8010 for that