DRILL-7292: Remove V1 and V2 text readers
Drill 1.16 introduced the "V2" text reader based on the row set
and provided schema mechanisms. V3 was available by system/session
option as the functionality was considered experimental.
The functionality has now undergone thorough testing. This commit makes
the V3 text reader available by default, and removes the code for the
original "V1" and the "new" (compliant, "V2") text reader.
The system/session options that controlled reader selection are retained
for backward compatibility, but they no longer do anything.
Specific changes:
* Removed the V2 "compliant" text reader.
* Moved the "V3" to replace the "compliant" version.
* Renamed the "complaint" package to "reader."
* Removed the V1 text reader.
* Moved the V1 text writer (still used with the V2 and V3 readers)
into a new "writer" package adjacent to the reader.
* Removed the CSV tests for the V2 reader, including those that
demonstrated bugs in V2.
* V2 did not properly handle the quote escape character. One or two unit
tests depended on the broken behavior. Fixed them for the correct
behavior.
* Behavior of "messy quotes" (those that appear in a non-quoted field)
was undefined for the text reader. Added a test to clearly demonstrate
the (somewhat odd) behavior. The behavior itself was not changed.
Reran all unit tests to ensure that they work with the now-default V3
text reader.
closes #1806
