Support longer unit test names + improve error handling in unit test construction

[MichelleArk]

resolves #9015

Problem

On Postgres, even modestly long test names (~20 characters) were hitting the "Relation name '{}' is longer than 63 characters" during construction of the 'actual' unit test result.

This is because we were creating model names and unique_ids in the unit test manifest out of the concatenation of the original model name, test name, and model being tested name to prevent key collision in the unit test manifest.

Solution

Now that we are creating a unit test manifest per unit test definition, there is no risk of key collisions if we just use the model name! This PR propagates those changes through and adds tests to ensure expected behaviour when:

• there are duplicate test names within a model (error)
• there are duplicate test names across models (pass, selection tested as well)
• a generally "invalid" test configuration (e.g. wrong data type in given input)
• right-size (pass) or long (fail, with handled exception) on postgres

Checklist

• I have read the contributing guide and understand what's expected of me
• I have run this code in development and it appears to resolve the stated issue
• This PR includes tests, or tests are not required/relevant for this PR
• This PR has no interface changes (e.g. macros, cli, logs, json artifacts, config files, adapter interface, etc) or this PR has already received feedback and approval from Product or DX
• This PR includes type annotations for new and modified functions

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Comparison is base (321031c) 86.98% compared to head (0ca8270) 86.93%.

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #9396      +/-   ##
==========================================
- Coverage   86.98%   86.93%   -0.05%     
==========================================
  Files         187      187              
  Lines       24947    24954       +7     
==========================================
- Hits        21699    21694       -5     
- Misses       3248     3260      +12     

Flag	Coverage Δ
integration	84.31% <100.00%> (-0.12%)	⬇️
unit	63.24% <26.66%> (-0.01%)	⬇️

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