fix group by queries on system tables with limit or the same aggregation twice
Merge pull request #1414 from crate/b/fix_group_with_limit

fix group by queries on system tables with limit or the same aggregation...
fix flaky blob coverage
Merge pull request #1416 from crate/m/flaky_blob_coverage

fix flaky blob coverage
do not account ram on projector instantiation
always reset cluster settings after test run
disallow indirect updating of nested clustered by columns
add RelationOutput symbol and ExpressionAnalyzer

This commit adds a RelationOutput, ExpressionAnalyzer and a
RelationOutputResolver.

The ExpressionAnalyzer can be used to convert Expression
(from SQL AST) into a Symbol. Using composition over
inheritance makes it possible to easier handle nested
relations and re-use the ExpressionAnalyzer for different
sources.

The DataStatementAnalyzer is now marked as deprecated and
shouldn't be used anymore.
use ExpressionAnalyzer in CopyStatementAnalyzer
change Delete Analysis to relation structure

DeleteAnalyzedStatement now has a relation as source/target
instead of tableInfo.

In case of bulk operations there are now longer nested full
blown AnalyzedStatements but only multiple WhereClauses.
change update analyzer to have sourceRelation and use relationAnalyzer/expressionAnalyzer