Fix dependsOn bug when string is not an asset

[erikn69]

Fix dependsOn bug when string is not an asset or when dependency is empty

• Code fixes
• Better validation on isJs, isCss, isBonsai
• Avoid adding same namespace to all files by mistake
  

  bonsai/src/Assets.php

  Lines 43 to 45 in 466603f

  	foreach ($assets as $asset) {
  	$this->add($asset, $namespace);
  	}

• Avoid code duplicity on foreachs
  

  bonsai/src/Assets.php

  Line 43 in 466603f

  foreach ($assets as $asset) {

  
  

  bonsai/src/Assets.php

  Line 165 in 466603f

  foreach ($assets as $asset => $meta) {

  
  

  bonsai/src/Assets.php

  Line 201 in 466603f

  foreach ($assets as $path => $meta) {

• Added missing return type on parseBonsai
  

  bonsai/src/Assets.php

  Line 194 in 466603f

  * @return Assets

  
  

  bonsai/src/Assets.php

  Line 211 in 466603f

  return;

• Fix bug in dependsOn when by mistake you Bonsai::add a non asset file like favico.ico and it has dependency with dependsOn, it adds the dependency to the las asset added before favico.ico,
  so if it is not asset clean lastAddedAsset property with $this->lastAddedAsset = '';
  

  bonsai/src/Assets.php

  Lines 48 to 52 in 466603f

  	} elseif ($this->isAsset($assets)) {
  	$this->addAsset($assets, $namespace);
  	}
  	return $this;

• Support arrays on parseBonsai, now is posible to do this

Bonsai::add(['file1.css', 'file2.css'])
Bonsai::add(['file1.css', 'file2.css' => ['namespace' => 'test']])
Bonsai::add(['file1.css' => null, 'file2.css' => ['namespace' => 'test']])
Bonsai::add(['file1.css' => ['namespace' => 'test'], 'file2.css' => ['dependency' => 'test']])

@kaidesu it works the same, just validations added and it's better now