Improve sed patch to work without gsed

[Samueru-sama]

Related to #1199

Now am is able to install apps when there is only bsd sed without gnu sed, tested without and with gsed on chimera linux (bsd userland):

(Note the broken sed detected message is for testing, I put it where the variable about sed gets set)

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Explanation:

• We check the version of sed, if it is not gnu sed the variable NO_SED_I=true gets set.

• The sed function will check for if [ "$NO_SED_I" = true ] && [ "$1" = '-i' ]; then, if both a true it tries to see if we have gsed, if true it uses gsed by default.

• If there is no gsed it then applies a workaround that drops the -i flag (shift) and puts the sed command in a variable $tmpsedYYY and finally that variable replaces the file we just edited echo "$tmpsedYYY" > "$1" all while doing a some sanity checks.

• If for some reason something goes wrong an error message explaining that situation and asking the error to install gsed is given.