fix(discovery): search universe index alias instead of _all

[sudo-suhas]

• Run search queries against the 'universe' index alias instead of _all.
• During the asset upsert in discovery repo, use a single index operation instead of the bulk update. Avoid triggering a refresh for each update as it can be quite costly.
• Improve contextual information in error for discovery repository update and delete operations.
• Always drain the response body in discovery repo to help with connection reuse.

[coveralls]

Pull Request Test Coverage Report for Build 4675585094

• 54 of 97 (55.67%) changed or added relevant lines in 4 files are covered.
• 7 unchanged lines in 1 file lost coverage.
• Overall coverage decreased (-0.4%) to 85.83%

---

Changes Missing Coverage	Covered Lines	Changed/Added Lines	%
internal/store/elasticsearch/es.go	12	17	70.59%
core/asset/errors.go	7	13	53.85%
internal/store/elasticsearch/discovery_repository.go	25	57	43.86%
<!--	Total:	54	97	55.67%	-->

Files with Coverage Reduction	New Missed Lines	%
internal/store/elasticsearch/discovery_repository.go	7	61.76%
<!--	Total:	7		-->

Totals
Change from base Build 4540668839:	-0.4%
Covered Lines:	5070
Relevant Lines:	5907

---

💛 - Coveralls