Fix large imap_content event warning by truncating the email text body to 2 KiB

[jbouwh]

Breaking change

The use of imap_content event could break for users that want to parse data from larger email messages from the part that is truncated. Only the first 2048 bytes of the message body (2 KiB) will be available.

Proposed change

Limits the size of the email text body that will be available in the event data or an imap_content event.
We should avoid large text bodies to be passed as event. The size of body text will be truncated to 2 KiB.
Large messages will lead to event data becoming to large, causing events not to be processed and warnings in the log about the size. A PR to update the documentation is added.

Type of change

• Dependency upgrade
• Bugfix (non-breaking change which fixes an issue)
• New integration (thank you!)
• New feature (which adds functionality to an existing integration)
• Deprecation (breaking change to happen in the future)
• Breaking change (fix/feature causing existing functionality to break)
• Code quality improvements to existing code or addition of tests

Additional information

• This PR fixes or closes issue: fixes #
• This PR is related to issue:
• Link to documentation pull request: Limit imap_content event email body text data home-assistant.io#27150

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• The code change is tested and works locally.
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[home-assistant]

Hey there @engrbm87, mind taking a look at this pull request as it has been labeled with an integration (imap) you are listed as a code owner for? Thanks!

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[frenck]

Thanks, @jbouwh 👍

../Frenck