Make CSV imports compatible with a wider possibility of CSV files

[ColinW520]

So, this isn't exactly a bug, but it's still aberrant behavior. The importer is currently extremely strict regarding the import file types it is willing to work with. Notably, it rejects anything that isn't a PURE CSV file, including Excel-exported csv's, plaintext csvs, and more. Believe it or not ( I know, it's stupid ) -- almost every word processing application encodes csv files differently...for some reason.

To make contact imports more useful for ALL, we need to accept a wider array of file types. This gets tricky -- because we still need to be able to parse the thing, and for that we need it to be amenable to csv-ish commands.

This is the first in a range of issues around imports, including better progress transparency, error messages, and more.

Here are the test cases we need to support:

• As a Windows user, when I save a properly formatted EXCEL spreadsheet without any extraneous commas as a "CSV", then I should be able to import that sheet.
• As an OSX user, when I save a properly formatted EXCEL spreadsheet without any extraneous commas as a "CSV", then I should be able to import that sheet.
• As CHROME user, when I save a properly formatted GOOGLE SHEETS spreadsheet without any extraneous commas as a "CSV", then I should be able to import that sheet.

Bonus points: write Meta tests that support these requirements.

[ColinW520]

@browning25 -- I was able to test using Chrome and OSX. Can you test Windows?

[browning25]

I could not get the test file to upload. Can you double check to make sure I have the formatting correct? I tried every variation of CSV I could save the file as. No luck. (The attached file is XLSX, but I tried uploading CSV files, Github doesnt support CSV file sharing).

TMT Test Upload.xlsx

[ColinW520]

@browning25 we're going to need to test that live. It's gotta work from a Windows machine to an actual server IMO

[ColinW520]

@browning25 -- i made more changes. I'm still not 100% confident I can test this effectively though. Would you mind giving it another whirl?

[browning25]

@ColinW520 -- I was able to successfully upload a CSV file.

1. The first upload added a new person successfully.
2. Second upload contained a name/info that was already loaded, just had a new tag added (it updated properly).
3. The third upload changed the spelling of a last name, but kept all the other information the same. It properly updated the last name and kept everything else the same (no duplicate was created - great work!)
4. I could not download the example file, however

I think this has been adequately addressed!

[ColinW520]

Awesome. Download file button resolved tonight. Close it if you're satisfied!

[browning25]

@ColinW520 -- I was able to download the spreadsheet. Only thing I noticed was that on my spreadsheet, it had Derek Schillaci's actual phone number on it. Is this the same spreadsheet that everyone will see when they download a sample file? If so, we need to change Derek's phone number just in case. Otherwise, looks great and ready to close.

[ColinW520]

made changes and saved -- should be closable

[browning25]

Verified the changes and ready to close.