Feat(auto-align): Add support for math equation auto-alignment + tests

[Eagle4398]

Add support for rapid fast auto-alignment of equations when typing.

• supports any math equations
• works within groups or "commands" e.g. a _ (a = b %ali%) --> a _ (a = & b \ & %cursor%)
• differentiates between equation alignment (selects last equation sign) and logical operator alignment (selects first operator) depending on the symbol chosen for the following line e.g.

a = b = c = d ali --> a = b = c = & d  \n =  & cursor
a <==> b <==> c <===> d --> a <==> & b <==> c <===> d \ <==> ^

The tests characterize behavior:

    ['inline-align-naive'] = ali_wrapper('$ x = a\\C $', "$ x = & a \\\n = &  $"),
    ['multiline-align-naive'] = ali_wrapper('$\\\n x = a\\C \\\n$', "$\\\n x = & a \\\n  = &  \\\n$"),
    ['subscript-align'] = ali_wrapper('$\\\n a = b + sum_( k = 0\\C)\\\n$', "$\\\n a = b + sum_( k = & 0 \\\n  = & )\\\n$"),
    ['subscript-align-2'] = ali_wrapper('$\\\n a = b + sum_( k = 0\\C)\\\n$', "$\\\n a = b + sum_( k = & 0 \\\n    & )\\\n$", " "),
    ['and-test'] = ali_wrapper('$ x = a\\C $', "$ & x = a \\\n and  &  $", "and"),
    ['or-test'] = ali_wrapper('$ x = a\\C $', "$ & x = a \\\n or  &  $", "or"),
    ['iff-test'] = ali_wrapper('$ x = a\\C $', "$ & x = a \\\n <==> &  $", "<==>"),
    ['==>-test'] = ali_wrapper('$ x = a\\C $', "$ & x = a \\\n ==> &  $", "==>"),

    ['multiple-operators'] = ali_wrapper('$ A <==> B <==> C <==> D\\C $', "$ A <==> & B <==> C <==> D \\\n ==> &  $", "==>"),
    ['multiple-operators2'] = ali_wrapper('$ A = B <==> C = D\\C $', "$ A = B <==> & C = D \\\n ==> &  $", "==>"),
    ['multiple-operators3'] = ali_wrapper('$ A = B <==> C = D\\C $', "$ A = B <==> C = & D \\\n = &  $"),

    ['ignore_eq_in_fun'] = ali_wrapper('$ norm(a = b)\\C $', "$ & norm(a = b) \\\n = &  $"),
    ['ignore_eq_in_grp'] = ali_wrapper('$ a_(a = b)\\C $', "$ & a_(a = b) \\\n = &  $"),

TODO

• Typstyle adherence (get character count till ampersand in preceding line and insert artifical whitespaces at beginning of line)