v: forbid function parameter names, shadowing imported module names

[ChAoSUnItY]

• fix Forbid parameters with same name as one of the imported modules #17209, forbids function parameter names shadowing imported module names.
• • Including function parameter, function name, and function receiver's name (anonymous function works in same way)
• Add output test
  fn_param_import_sym_conflict.vv

import arrays
import maps

// FnDecl
fn x(arrays []int) {

}

struct Foo {
}

// FnDecl with receiver
fn (arrays Foo) x() {

}

fn (arrays Foo) y(maps []int) {

}

fn (foo Foo) z(arrays []int) {
	
}

// AnonFn
fn y() {
	_ := fn (arrays []int) {}
}

vlib/v/checker/tests/fn_param_import_sym_conflict.vv:1:8: warning: module 'arrays' is imported but never used
    1 | import arrays
      |        ~~~~~~
    2 | import maps
    3 |
vlib/v/checker/tests/fn_param_import_sym_conflict.vv:2:8: warning: module 'maps' is imported but never used
    1 | import arrays
    2 | import maps
      |        ~~~~
    3 |
    4 | // FnDecl
vlib/v/checker/tests/fn_param_import_sym_conflict.vv:5:5: error: duplicate of an import symbol `arrays`
    3 |
    4 | // FnDecl
    5 | fn x(arrays []int) {
      |     ~~~~~~
    6 |
    7 | }
vlib/v/checker/tests/fn_param_import_sym_conflict.vv:13:4: error: duplicate of an import symbol `arrays`
   11 |
   12 | // FnDecl with receiver
   13 | fn (arrays Foo) x() {
      |    ~~~~~~
   14 |
   15 | }
vlib/v/checker/tests/fn_param_import_sym_conflict.vv:17:5: error: duplicate of an import symbol `arrays`
   15 | }
   16 |
   17 | fn (arrays Foo) y(maps []int) {
      |     ~~~~~~
   18 |
   19 | }
vlib/v/checker/tests/fn_param_import_sym_conflict.vv:21:16: error: duplicate of an import symbol `arrays`
   19 | }
   20 |
   21 | fn (foo Foo) z(arrays []int) {
      |                ~~~~~~
   22 |
   23 | }
vlib/v/checker/tests/fn_param_import_sym_conflict.vv:23:11: error: duplicate of an import symbol `arrays`
   21 | // AnonFn
   22 | fn y() {
   23 |     _ := fn (arrays []int) {}
      |              ~~~~~~
   24 | }

Note

This is a breaking change, most modules will be affected by this change, including vinix, stdlib etc.

[spytheman]

Good work.

[spytheman]

I think, that the CI will pass now (it did in the AoC repo), and I do not want to delay merging this further, because new code is added to the other repos, and it will be better to make all use the more restrictive compiler sooner than later, since that will simplify the IdeaJ plugin as well as VLS.