fix(sql-check): failed to detect pk dropping when drop it as constraint

[yhilmare]

What type of PR is this?

type-bug

What this PR does / why we need it:

primary key can be defined as a constraint, just like this:

create table abcd(
    id varchar2(64),
    constraint abcd primary key (id)
);

so that we can drop this pk by dropping constraint:

alter table abcd drop constraint abcd;

this pr consider of this situation~

Which issue(s) this PR fixes:

Fixes #1875 #1871 #1891 #1893 #1906

Special notes for your reviewer:

Additional documentation e.g., usage docs, etc.:

[PeachThinking]

LGTM