Update .NET 7 Unicode data to version 14.0.0

[GrabYourPitchforks]

The Unicode Standard version 14.0.0 is tentatively scheduled for September 2021. As per usual, since the .NET runtime carries a copy of Unicode-derived data, we should update our data files to match version 14.0.0 when it's released.

This will affect the following APIs:

• System.Globalization.StringInfo
• System.Globalization.CharUnicodeInfo
• System.Text.Encodings.Web.*
• System.Text.Json.* (since it depends on System.Text.Encodings.Web)

For instructions on how to update the runtime-carried Unicode data files, consult the GenUnicodeProp docs and the STEW docs. Also update the UnicodeUcdVersion data throughout our .csproj files (see samples).

See #2378 for the changes we made for Unicode 13.0.0 in .NET 5.

We should also keep an eye out for any changes to UAX#29 that might be part of the Unicode 14.0.0 wave. Our tools will automatically pick up any changes to a code point's Grapheme_Cluster_Break property, but if the algorithm in Sec. 3.1.1 changes as part of Unicode 14.0.0 then we may need to update the logic in TextSegmentationUtility.cs.

Tagging subscribers to this area: @tarekgh, @safern, @krwq
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Details

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Issue meta data

Issue content:	The Unicode Standard version __14.0.0__ [is tentatively scheduled](https://home.unicode.org/unicode-14-0-delayed-for-6-months/) for September 2021. As per usual, since the .NET runtime carries a copy of Unicode-derived data, we should update our data files to match version 14.0.0 when it's released. This will affect the following APIs: System.Globalization.StringInfo System.Globalization.CharUnicodeInfo System.Text.Encodings.Web.* System.Text.Json.* (since it depends on System.Text.Encodings.Web) For instructions on how to update the runtime-carried Unicode data files, consult the GenUnicodeInfo docs and the STEW docs. Also update the UnicodeUcdVersion data throughout our .csproj files (see samples). See #2378 for the changes we made for Unicode 13.0.0 in .NET 5. We should also keep an eye out for any changes to UAX#29 that might be part of the Unicode 14.0.0 wave. Our tools will automatically pick up any changes to a code point's Grapheme_Cluster_Break property, but if the algorithm in Sec. 3.1.1 changes as part of Unicode 14.0.0 then we may need to update the logic in TextSegmentationUtility.cs.
Issue author:	GrabYourPitchforks
Assignees:	-
Milestone:	[object Object]

[tarekgh]

@GrabYourPitchforks just checkin, are you planning for doing that soon?

[GrabYourPitchforks]

Moving this to 7.0 so that the dates line up correctly.

[GrabYourPitchforks]

Now that we're within a month of Unicode 14.0's release, I gave https://unicode.org/versions/Unicode14.0.0/ another look. There's a new block Arabic Extended-B being added to the BMP. Our ingestion tools will automatically create a new API to support this block, so I opened #57609 to track the API review process for it.

We're still waiting for the PDFs to be published in case there were any changes to Sec. 5.8 (which controls string.ReplaceLineEndings). So far we're still good on UAX#29 (which controls StringInfo).

[tarekgh]

@GrabYourPitchforks what is remaining to do here?