sum string projection as integer of bool

[rks0nax]

Description of change

Fixes issue - #93
The change allows user to specify string projection, instead of just integer values

A sample projection that didn't work before and should be working after merging this PR
{"name": "$personName"}

QA steps

• automated tests passing
• manual qa steps passing (list below)

Risks

Rollback steps

• revert this branch

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[dmcquay]

I need this fix badly. Looks like this has been ready to merge for a long time. What's the hold up?
@rks0nax Thanks for reporting and contributing the fix! Was very happy to see this.

[dmcquay]

@cosimon can you provide an update on this?

[dmcquay]

In the Stitch troubleshooting documentation, their recommended course of action for column or table name too long loading errors is to omit the table from the source, rename at the source or switch to a different destination.
https://www.stitchdata.com/docs/troubleshooting/destinations/destination-loading-error-reference#column-name-limit

This PR would allow us to instead use aliases in mongo projections to address the issue, which is MUCH less painful. Switching the destination of our entire data lake is obviously quite painful. Renaming at the source is painful because the source is an app tier DB used in a monolithic architecture -- hard to change. And simply omitting the data obviously only works well if I don't NEED the data in my data lake.

Just providing context on why this PR is valuable to me.

[dmcquay]

And please notice that the change is:

1. Only one line
2. Seems to me like disallowing string values here was an accident in the first place, not strategic. So this really just feels like a bug fix.

Seems like it is a no brainer to get this merged.