uritemplate.parser: add initial tokenLeftBrace support

Signed-off-by: Alejandro Mery <amery@geeks.cl>
uritemplate: implement exprCapture.addToken()

Signed-off-by: Alejandro Mery <amery@geeks.cl>
uritemplate.expression add pointer to the parser in addToken() call

Signed-off-by: Alejandro Mery <amery@geeks.cl>
uritemplate: move expr.addToken() into the parser module

Signed-off-by: Alejandro Mery <amery@geeks.cl>
uritemplate.lexer: emit(tokenRightBrace)

Signed-off-by: Alejandro Mery <amery@geeks.cl>
uritemplate.parser: add basic tokenRightBrace support

Signed-off-by: Alejandro Mery <amery@geeks.cl>