Parenthesis are added to end of UDF in DDL statements

[LarnuUK]

Issue Type: Bug

When using Tab to complete the name of an object, whenever a reference to a User-Defined Function (UDF) is made, parenthesis (()) are automatically added to the end, even if that would be invalid syntax.

If you are performing a DDL statement, such as a DROP, that is unwanted. These should only be added when needed (or possibly not at all).

Example:

Azure Data Studio version: azuredatastudio 1.14.1 (f9b968c, 2019-12-24T02:35:43.481Z)
OS version: Linux x64 5.3.0-24-generic

System Info

Item	Value
CPUs	Intel(R) Core(TM) i7-8700 CPU @ 3.20GHz (12 x 4299)
GPU Status	2d_canvas: enabled flash_3d: enabled flash_stage3d: enabled flash_stage3d_baseline: enabled gpu_compositing: enabled metal: disabled_off multiple_raster_threads: enabled_on oop_rasterization: disabled_off protected_video_decode: unavailable_off rasterization: disabled_software skia_renderer: disabled_off surface_control: disabled_off surface_synchronization: enabled_on video_decode: unavailable_off viz_display_compositor: enabled_on viz_hit_test_surface_layer: disabled_off webgl: enabled webgl2: enabled
Load (avg)	2, 2, 2
Memory (System)	15.56GB (0.76GB free)
Process Argv	--no-sandbox --unity-launch
Screen Reader	no
VM	0%

Extensions (17)

Extension	Author (truncated)	Version
vsc-material-theme	Equ	30.0.0
admin-pack	Mic	0.0.2
admin-tool-ext-win	Mic	0.0.2
agent	Mic	0.45.0
cms	Mic	0.6.0
dacpac	Mic	1.1.0
import	Mic	0.12.0
managed-instance-dashboard	Mic	0.3.9
profiler	Mic	0.11.0
query-history	Mic	0.1.0
schema-compare	Mic	1.1.0
server-report	Mic	0.2.1
whoisactive	Mic	0.1.3
azdata-sanddance	msr	1.3.9
material-icon-theme	PKi	3.9.0
sql-search	Red	0.3.6
vscodeintellicode	Vis	1.2.1