Remove redundant casting functions

[Anish9901]

Description

We have a lot of casting functions in 45_msar_type_casting.sql which are redundant.
E.g. Casting to uuid doesn't require 3 function with different parameter types overloaded for each string like type. A casting function withtext param can handle all string types including text, character and varchar. This might also be true for other types numeric but needs to be thoroughly tested.

mathesar=# CREATE OR REPLACE FUNCTION msar.cast_to_uuid(text)
RETURNS uuid
AS $$
BEGIN
  RETURN $1::uuid;
END;
$$ LANGUAGE plpgsql RETURNS NULL ON NULL INPUT;
CREATE FUNCTION

mathesar=# select msar.cast_to_uuid('bc2166dd-ca1d-41c6-9c66-610f844ca139');
             cast_to_uuid             
--------------------------------------
 bc2166dd-ca1d-41c6-9c66-610f844ca139
(1 row)

mathesar=# select msar.cast_to_uuid('bc2166dd-ca1d-41c6-9c66-610f844ca139'::char(36));
             cast_to_uuid             
--------------------------------------
 bc2166dd-ca1d-41c6-9c66-610f844ca139
(1 row)

mathesar=# select msar.cast_to_uuid('bc2166dd-ca1d-41c6-9c66-610f844ca139'::varchar);
             cast_to_uuid             
--------------------------------------
 bc2166dd-ca1d-41c6-9c66-610f844ca139
(1 row)

Expected behavior

We should ideally remove all of string like varients of casting functions and only keep their text version. If there is a possibility to do the same for non string like types as well we should consider that.

[Anand1923]

@Anish9901 Is this an open issue? I would like to take it up.

[zackkrida]

Hi @Anand1923 this issue is open and marked as help wanted so feel free to work on it. You can reach out to @Anish9901 here if you have any questions while implementing. Thank you!

[Anish9901]

@Anand1923 If you work on this, please try to create multiple small PRs(e.g. 1 PR for 2-3 cast type) instead of one really big PR with a lot of deletions, this way it would be easy for us to review and merge your PRs quicker.