Fix null committee_name in ts_vector column used by q_filer

[hcaofec]

What we’re after

When there is null value in committee name, especially for unverified committees, the ts_vector column that includes committee name needs to use coalesce function to handle this scenario.

This is for filings an reports endpoint.

https://www.fec.gov/data/filings/?data_type=processed&q_filer=C00780197

https://api.open.fec.gov/v1/filings/?sort=-receipt_date&sort_hide_null=false&sort_nulls_last=false&per_page=20&page=1&sort_null_only=false&q_filer=C00780197&api_key=DEMO_KEY

Related ticket(s)

CMS ticket #5707
#5160

endpoint list with keyword text filter being added

(Include the tickets that either came before, after, or are happening in tandem with this new ticket)
#5219
#5247
PR #5248

Action item(s)

• Add coalesce to ofec_filings_all_mv and other reports mv

Completion criteria

• create migration files