Allow multiple instances of the same exposed filter form on a single page

We tried patch #32 and seems to work disabling the caches, but when we enabled the drupal caches, the form has the ids duplicated.
So seems to be also related to cache.

Rerolled patch for 9.5.x

#38 does not get applied to 10.1x so i made it compatible so now it can applies cleany. creating interdiff giving some error so i couldn’t able to update it here!

Reroll for 9.5.x

Previously tagged for tests that are still needed.

Also issue summary could use some love.

Re-rolled 10.1.x / 11.x

Patch on #39 was already meant for 10.1.x and 11.x and it applies and passes the tests. However, as said in #43 we still need tests.