fix warnings in dolt sql shell

[jycor]

This PR fixes a bug where warnings were incorrectly being suppressed in the dolt sql shell.
The bug is caused by the shell making queries to check if the working set is dirty, what database we're on, and what branch we're on. The fix is to set a special flag in the session to not clear the warnings for those specific queries.

companion pr: dolthub/go-mysql-server#2605

fixes: #8016

[fulghum]

LGTM!

[coffeegoddd]

@fulghum DOLT

comparing_percentages
100.000000 to 100.000000

version	result	total
e64da54	ok	5937457

version	total_tests
e64da54	5937457

correctness_percentage
100.0

[coffeegoddd]

@jycor DOLT

comparing_percentages
100.000000 to 100.000000

version	result	total
135cca2	ok	5937457

version	total_tests
135cca2	5937457

correctness_percentage
100.0

[coffeegoddd]

@jycor DOLT

comparing_percentages
100.000000 to 100.000000

version	result	total
bc48aac	ok	5937457

version	total_tests
bc48aac	5937457

correctness_percentage
100.0

[coffeegoddd]

@jycor DOLT

comparing_percentages
100.000000 to 100.000000

version	result	total
3718ade	ok	5937457

version	total_tests
3718ade	5937457

correctness_percentage
100.0

[coffeegoddd]

@jycor DOLT

comparing_percentages
100.000000 to 100.000000

version	result	total
ff1b430	ok	5937457

version	total_tests
ff1b430	5937457

correctness_percentage
100.0