Extend stray tag check

[dc-almeida]

Partial resolution of #401.
Expands on stray tag check in code names, adding checks for brackets for all code attributes.
Recursively checks list and dict attributes for strings.
Tests expanded.

[danielhuppmann]

Nice, see a suggestion for cleaner test-code inline.

Also, I suggest to also add a test-case where a stray tag is in a attribute-string, like

- Primary Energy:
     definition: Total primary energy { consumption
     unit: EJ/yr

[dc-almeida]

Nice, see a suggestion for cleaner test-code inline.

Also, I suggest to also add a test-case where a stray tag is in a attribute-string, like

- Primary Energy:
     definition: Total primary energy { consumption
     unit: EJ/yr

Initially I had added one, but removed it since the original test does so by checking for the stray tag in the code name. Can easliy add another more explicit one.

[danielhuppmann]

One more little suggestionfor better error messages, then good to be merged.

[danielhuppmann]

Suggested change

	f"Unexpected bracket in codelist: {code.name}."
	f"Unexpected bracket in {self.name} '{code.name}'."

[danielhuppmann]

Suggested change

	("char_in_str", r"Unexpected bracket in codelist: Primary Energy\|{Feul}"),
	("char_in_str", r"Unexpected bracket in variable 'Primary Energy\|{Feul}'"),

[danielhuppmann]

Suggested change

	("char_in_list", r"Unexpected bracket in codelist: Share\|Coal"),
	("char_in_list", r"Unexpected bracket in variable 'Share\|Coal'"),

[danielhuppmann]

Suggested change

	("char_in_dict", r"Unexpected bracket in codelist: Primary Energy"),
	("char_in_dict", r"Unexpected bracket in variable 'Primary Energy'"),