Add rules for subprogram instantiation declarations

[JHertz5]

Is your feature request related to a problem? Please describe.
For subprogram instantiation declarations, e.g.

function my_func is new my_func
  generic map (
    test => c_test
  );

there are very few rules that act on this code.

For example, I can have the following, very ugly code

        FUNCTION MY_FUNC2 IS NEW MY_FUNC
GENERIC
MAP (
TEST => C_TEST
)
;

and running vsg --fix on it produces

  function MY_FUNC2 IS NEW MY_FUNC
GENERIC
MAP (
TEST => C_TEST
)
;

where ideally, I would like it to be fixed to the first snippet in this issue.

Describe the solution you'd like
I would like a set of rules to be created for subprogram instantiation declarations to enforce case, alignment, whitespace, etc.

[JHertz5]

See #1306 for equivalent work on package instantiation declarations.

[JHertz5]

I am planning to raise a PR for this, I'm just aware that I've created quite a pile of PRs (sorry!), so I'm planning to give @jeremiah-c-leary a chance to clear some of those before adding more to the pile!

[jeremiah-c-leary]

I am planning to raise a PR for this, I'm just aware that I've created quite a pile of PRs (sorry!), so I'm planning to give @jeremiah-c-leary a chance to clear some of those before adding more to the pile!

I starting to catch up so keep them coming.

--Jeremy

[JHertz5]

I'm going to create a list of issues from this one to make the PRs smaller. The package instantiation declaration rules were broken down into the following list.

Subtask	Issue	PR
Case rules (+ setup)	#1322	#1326
Indent and blank line rules	#1323	#1327
Structure rules	#1324	#1328
Whitespace rules	#1325	#1329
Naming rules	#1330	#1331

We can basically use the same list of rules for subprogram instantiations, although we won't need naming rules, since there are no prefix/suffix naming rules for subprograms.

For the package instantiation declaration rules, I tried to use a "parent" issue with several "subtask" issues. This didn't works so well because we had to manually reopen/close the "parent" issue. Instead, I'll just use this issue to implement the final rules, so that it can be marked as closed when all the rules are completed without causing extra hassle.

Subprogram instantiation declaration rule issues

Subtask	Issue	PR
Case rules (+ setup)	#1364	#1371
Indent and blank line rules	#1365	#1379
Structure rules	#1366	#1380
Whitespace rules	#1318 (this issue)	#1381

[JHertz5]

Once the others are complete, this issue will be used to add rules for whitespace for subprogram instantiation declarations, e.g. correcting this

  function    my_func     is     new    my_generic_func
    generic map (
      test => 2
    );

  procedure    my_proc     is     new    my_generic_proc
    generic map (
      test => 2
    );

to this

  function my_func is new my_generic_func
    generic map (
      test => 2
    );

  procedure my_proc is new my_generic_proc
    generic map (
      test => 2
    );