[Powerautomate] Add size text sumary and body

[marssilva]

Description

Adding the feature that adjusts the size of the summary and body in the ms_power_automate alert.

Checklist

Created two tests for new feature and adjusted documentation.

• [x] I have reviewed the contributing guidelines.
• [x ] I have included unit tests for my changes or additions.
• [x] I have successfully run make test-docker with my changes.
• [x] I have manually tested all relevant modes of the change in this PR.
• [x] I have updated the documentation.
• [ ] I have updated the changelog.

[marssilva]

Hi @jertel, I made some adjustments to the size of the summary and the body of the text, in "teams" the summary doesn't show everything when the text is long.

[jertel]

Thanks for submitting this. Can you adjust the schema to use enums for those new values. Ex:

telegram_parse_mode: {type: string, enum: ['markdown', 'markdownV2', 'html']}

Also, please add this PR to the changelog. You can either add the second PR hyperlink to your existing entry, or create a new entry.

[marssilva]

Suggestions applied @jertel.