Drop type support

[Langes01x]

Expected Behaviour

SQLFluff using T-SQL (or ANSI) dialect should be able to parse a create type statement. Create type is defined in ANSI but drop type isn't.

Refer to T-SQL syntax here: https://docs.microsoft.com/en-us/sql/t-sql/statements/drop-type-transact-sql?view=sql-server-ver15

Observed Behaviour

SQLFluff fails to parse the statement

Steps to Reproduce

echo drop type typeName| sqlfluff parse -

[L:  1, P:  1]      |file:
[L:  1, P:  1]      |    unparsable:                                               !! Expected: 'FileSegment'
[L:  1, P:  1]      |        raw:                                                  'drop'
[L:  1, P:  5]      |        whitespace:                                           ' '
[L:  1, P:  6]      |        raw:                                                  'type'
[L:  1, P: 10]      |        whitespace:                                           ' '
[L:  1, P: 11]      |        raw:                                                  'typeName'
[L:  1, P: 19]      |    newline:                                                  '\n'

==== parsing violations ====
L:   1 | P:   1 |  PRS | Line 1, Position 1: Found unparsable section: 'drop type typeName'

Dialect

T-SQL (but also ANSI and maybe others too)

Version

SQLFluff - 0.8.1
Python - 3.10.0

Configuration

# Refer to https://docs.sqlfluff.com/en/stable/configuration.html#default-configuration for defaults
[sqlfluff]
dialect = tsql
templater = raw
sql_file_exts = .sql

[sqlfluff:rules]
allow_scalar = False
single_table_references = qualified

[sqlfluff:rules:L007]  # Operator location
operator_new_lines = before

[sqlfluff:rules:L010]  # Keyword capitalization
capitalisation_policy = upper

[sqlfluff:rules:L014]  # Identifier capitalization
extended_capitalisation_policy = pascal

[sqlfluff:rules:L030]  # Function capitalization
capitalisation_policy = lower

[sqlfluff:rules:L040]  # Null & Boolean capitalization
capitalisation_policy = lower

[sqlfluff:rules:L042]  # Subqueries
forbid_subquery_in = both

[sqlfluff:rules:L047]  # Count syntax
prefer_count_1 = True
prefer_count_0 = False

[jpy-git]

Will add this now