Simplify base TestCases

[1ucian0]

Removing the complexity in the TestCases class hierarchy. Additionally, removing the terra mentions.

[qiskit-bot]

One or more of the following people are relevant to this code:

• @Qiskit/terra-core

[coveralls]

Pull Request Test Coverage Report for Build 9790725826

Details

• 0 of 0 changed or added relevant lines in 0 files are covered.
• 26 unchanged lines in 3 files lost coverage.
• Overall coverage decreased (-0.04%) to 89.809%

---

Files with Coverage Reduction	New Missed Lines	%
crates/qasm2/src/expr.rs	1	94.02%
crates/qasm2/src/lex.rs	7	91.35%
crates/qasm2/src/parse.rs	18	96.69%

Totals
Change from base Build 9785044203:	-0.04%
Covered Lines:	65108
Relevant Lines:	72496

---

💛 - Coveralls

[ElePT]

I think it makes sense to remove the base class, I added two small wording suggestions, but LGTM.

[coveralls]

Pull Request Test Coverage Report for Build 9792154196

Warning: This coverage report may be inaccurate.

This pull request's base commit is no longer the HEAD commit of its target branch. This means it includes changes from outside the original pull request, including, potentially, unrelated coverage changes.

• For more information on this, see Tracking coverage changes with pull request builds.
• To avoid this issue with future PRs, see these Recommended CI Configurations.
• For a quick fix, rebase this PR at GitHub. Your next report should be accurate.

Details

• 0 of 0 changed or added relevant lines in 0 files are covered.
• 23 unchanged lines in 2 files lost coverage.
• Overall coverage decreased (-0.03%) to 89.817%

---

Files with Coverage Reduction	New Missed Lines	%
crates/qasm2/src/lex.rs	5	92.11%
crates/qasm2/src/parse.rs	18	96.69%

Totals
Change from base Build 9785044203:	-0.03%
Covered Lines:	65114
Relevant Lines:	72496

---

💛 - Coveralls

[1ucian0]

I added two small wording suggestions

accepting both.

[ElePT]

LGTM!