Add support for FROM <filename>, DELIMITER, and CSV HEADER options for COPY command

[poonai]

This PR adds support for delimiter and csv header options in copy command

Signed-off-by: password rbalajis25@gmail.com

[coveralls]

Pull Request Test Coverage Report for Build 1801328813

• 60 of 67 (89.55%) changed or added relevant lines in 3 files are covered.
• No unchanged relevant lines lost coverage.
• Overall coverage increased (+0.09%) to 90.413%

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Changes Missing Coverage	Covered Lines	Changed/Added Lines	%
src/ast/mod.rs	11	14	78.57%
src/parser.rs	19	23	82.61%

Totals
Change from base Build 1799434596:	0.09%
Covered Lines:	6809
Relevant Lines:	7531

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💛 - Coveralls

[alamb]

Thanks for the contribution @poonai . I had a question about CSV HEADER

the lint CI failures should be resolved if you merge up to main

[alamb]

I didn't think CSV HEADER was part of the syntax. Postgres seems to only support HEADER:

https://www.postgresql.org/docs/13/sql-copy.html

I think CSV is used as part of the FORMAT option, like

COPY ... FORMAT CSV ...

[poonai]

If you scroll down, you'll find the compatibility section. There you can find CSV HEADER spec.

Sure, I merge the main

[alamb]

Thanks again @poonai for the contribution. If/when people want further support for COPY options, we can always add it as a follow on PR