Feature/download call details

[virtualgill]

Issue #, if available: https://github.com/aws-samples/amazon-transcribe-live-meeting-assistant/issues/22

Description of changes:

• Additional of download buttons for summary and transcript that are visible once the meeting recording is complete.
• Option to download transcript as text or excel
• Option to download summary as text or to open email with summary (requires your browser/machine to have mailto: functionality correctly configured)

• Additionally linting rules were adjusted to allow for longer line lengths

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