Use outOfOffice calendar property instead of keywords filters

[Saul-R]

Description

On the shared calendar example, this removes the filters and logic around keywords and uses outOfOffice type events instead. These do not need to be filtered.

Motivation:

• No need to define/rely on keywords
• This is compatible with private calendars (where description of events might not be visible).

Is it been tested?

• Development testing done / Implemented in my company, been running for some time.

Checklist

• My code follows the style guidelines of this project
• I have performed a self-review of my own code
• I have performed a peer-reviewed with team member(s)
• I have commented my code, particularly in hard-to-understand areas
• I have made corresponding changes to the documentation
• My changes generate no new warnings
• Any dependent changes have been merged and published in downstream modules

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