Support for postgres String Constants with Unicode Escapes

[lovasoa]

fixes #1354

[coveralls]

Pull Request Test Coverage Report for Build 10144845572

Details

• 79 of 102 (77.45%) changed or added relevant lines in 7 files are covered.
• 1 unchanged line in 1 file lost coverage.
• Overall coverage decreased (-0.04%) to 89.184%

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Changes Missing Coverage	Covered Lines	Changed/Added Lines	%
src/dialect/generic.rs	1	2	50.0%
src/dialect/mod.rs	1	2	50.0%
src/dialect/postgresql.rs	1	2	50.0%
src/parser/mod.rs	4	5	80.0%
tests/sqlparser_postgres.rs	19	21	90.48%
src/ast/value.rs	14	17	82.35%
src/tokenizer.rs	39	53	73.58%

Files with Coverage Reduction	New Missed Lines	%
src/ast/value.rs	1	86.96%

Totals
Change from base Build 10144601977:	-0.04%
Covered Lines:	27277
Relevant Lines:	30585

---

💛 - Coveralls

[lovasoa]

I think the failed "lint" test is not related to the changes in this PR.

[git-hulk]

I think the failed "lint" test is not related to the changes in this PR.

Yes, I also mentioned in #1353 (comment)

[lovasoa]

I opened a separate PR for the clippy errors: #1357

[lovasoa]

@alamb , I just merged the ci fixes from main, the CI passes, this should be good to merge.

[alamb]

Thanks @lovasoa and @git-hulk