feat: add business_hours support for sla evaluation

[vishnu-narayanan]

Pull Request Template

Description

• Add support for respecting the business_hour setting in SLA policies

Changelog

• Business hours are used in evaluation only if the inbox configures business hours and a conversation is applied with an SLA policy that has only_during_business_hours set to true.
• If either inbox or sla_poliicy is missing business_hours, this will be evaluated normally

Fixes https://linear.app/chatwoot/issue/CW-3051/handle-business-hours-during-sla-evaluation

Type of change

Please delete options that are not relevant.

• New feature (non-breaking change which adds functionality)

How Has This Been Tested?

• Add new specs

Checklist:

• My code follows the style guidelines of this project
• I have performed a self-review of my code
• I have commented on my code, particularly in hard-to-understand areas
• I have made corresponding changes to the documentation
• My changes generate no new warnings
• I have added tests that prove my fix is effective or that my feature works
• New and existing unit tests pass locally with my changes
• Any dependent changes have been merged and published in downstream modules

[linear]

CW-3051 Handle business hours during SLA evaluation