refactor(SLA): Application of SLA and its fields

[nextchamp-saqib]

Problems Fixed:

• Hourly Job set_service_level_agreement_variance doesn't work since first parameter doctype is not passed
  • fix: Disabled Hourly Job
• Default Issue Priority is set as "Medium", which creates problems in finding an SLA
• Entity and Condition fields in SLA Form are confusing
  • fix: Added Dynamic Descriptions
• If "All Customer Group" is set SLA customer group, then if an Issue Customer which belongs to one of the decedent groups, SLA is not applied
• Response & Resolution Metrics doesn't consider Hold Time, if status changes from Replied to Closed
• SLA is always set as Failed in case if an Issue that was closed within SLA, is now opened after a long time.

Refactors:

• Remove Variance Metrics
• Split Ongoing Status into First Response Due & Resolution Due to better convey the SLA Status

[codecov]

Codecov Report

Merging #28550 (2f7d8ac) into develop (ef53eb7) will decrease coverage by 0.03%.
The diff coverage is 95.13%.

@@             Coverage Diff             @@
##           develop   #28550      +/-   ##
===========================================
- Coverage    55.27%   55.23%   -0.04%     
===========================================
  Files         1122     1122              
  Lines        66772    66759      -13     
===========================================
- Hits         36906    36875      -31     
- Misses       29866    29884      +18     

Impacted Files	Coverage Δ
erpnext/hooks.py	0.00% <ø> (ø)
erpnext/support/doctype/issue/issue.py	65.02% <0.00%> (+0.63%)	⬆️
...next/support/report/issue_summary/issue_summary.py	0.00% <ø> (ø)
...service_level_agreement/service_level_agreement.py	83.29% <95.80%> (+1.39%)	⬆️
erpnext/utilities/product.py	14.70% <0.00%> (-35.30%)	⬇️
erpnext/shopping_cart/product_info.py	30.30% <0.00%> (-21.22%)	⬇️
...e/shopping_cart_settings/shopping_cart_settings.py	65.38% <0.00%> (-1.93%)	⬇️
erpnext/stock/reorder_item.py	75.21% <0.00%> (-1.71%)	⬇️
erpnext/shopping_cart/product_query.py	61.19% <0.00%> (-1.50%)	⬇️
.../report/stock_projected_qty/stock_projected_qty.py	86.84% <0.00%> (-1.32%)	⬇️
... and 16 more

[nextchamp-saqib]

Closed #28752