Add Canadian French trademark symbols

[sdalmonte]

In Canada, the ™ and ® symbols have French-language equivalents, 🅪 (U+1F16A RAISED MC SIGN) and 🅫 (U+1F16B RAISED MD SIGN) respectively. I propose adding them as variants of trademark and trademark.registered, with a common suffix to indicate that their use is specific to French-language materials in Canada.

There are currently no symbols in sym.txt that are both region- and language-specific. Following the lead of variants of the peso and rupee currency symbols, the suffix could be .canadianfrench (or .canadian.french), but that’s quite long. For brevity I would suggest .frca, based on the ISO language code.

[MDLC01]

I would personally be in favor of introducing separate names, such as marquedecommerce and marquedeposee. I don't like those specific names because they are too long in my opinion, but I would prefer going in this direction.

[sdalmonte]

Having separate names makes sense to me. Since other trademark symbols (® and ℠) are listed under trademark, perhaps we should go with trademark.mc and trademark.md for consistency.

[sdalmonte]

Crossposting from #179 (comment):

I feel like any option requires some tradeoffs. Here's a few ideas:

symbols	pros	cons
trademark.mc trademark.md	concise, describes the appearance of the symbol	not semantic; doesn't make it clear that this is a region-specific symbol
trademark.commerce trademark.deposee	semantic (describes a French-only usage in French)	we don't currently use non-English terms in symbols; "deposee" is technically incorrect (should be "déposée", but symbols shouldn't contain accents); doesn't make it clear that this is a region-specific symbol
trademark.marquedecommerce trademark.marquedeposee	semantic (describes a French-only usage in French)	we don't currently use non-English terms in symbols; "deposee" is technically incorrect (should be "déposée", but symbols shouldn't contain accents); doesn't make it clear that this is a region-specific symbol; extremely long
trademark.canadianfrench trademark.registered.canadianfrench	matches the semantics of the other symbols under trademark and localized currency symbols (e.g. peso.philippine, rupee.tamil)	extremely long
trademark.canadian.french trademark.registered.canadian.french	matches the semantics of the other symbols under trademark and localized currency symbols (e.g. peso.philippine, rupee.tamil)	extremely long, potentially introduces ambiguity since there's no trademark.french / trademark.canadian symbol
trademark.frca trademark.registered.frca	semantic (using ISO locale code)	use of abbreviations is inconsistent with other locale/language-specific symbols
trademark.fr.ca trademark.registered.fr.ca	semantic (using ISO locale code)	use of abbreviations is inconsistent with other locale/language-specific symbols; potentially introduces ambiguity since there's no trademark.fr / trademark.ca symbol
marquedecommerce marquedeposee	spells out the abbreviation of the symbol	quite long; since it's not within trademark, we lose the semantics of trademark; we don't currently use non-English terms in symbols; "deposee" is technically incorrect (should be "déposée", but symbols shouldn't contain accents); doesn't make it clear that this is a region-specific symbol

Of these, I prefer trademark.frca/trademark.registered.frca or trademark.commerce/trademark.deposee. I'm open to other suggestions.