js: simplify journal.js with toggleClass, fix toggling of postings
js: simplify journal.js with toggleClass, fix toggling of postings

aumayr/beancount-web,aumayr/beancount-web,yagebu/fava,yagebu/fava,corani/beancount-web,corani/beancount-web,corani/beancount-web,yagebu/fava,aumayr/beancount-web,beancount/fava,beancount/fava,beancount/fava,yagebu/fava,beancount/fava,corani/beancount-web,aumayr/beancount-web,beancount/fava,yagebu/fava