The encrypt_text function should consume the plaintext message (a string) and rotation_amount (an integer) and produces a string where the text is encrypted as follows:

1. Convert the string to a list of integers using ord.
2. Rotate each integer of the string by rotation_amount amount. To rotate a value, use the following formula: rotated = (original+rotation-32) % 94 + 32. Hint: use a helper function.
3. Insert the tilde ASCII value (126, which translates to "~") after every integer less than 48. Hint: Append more than once.
4. Convert the list of integers back to a string using chr.

The decrypt_text function should consume the encrypted message (a string) and rotation_amount (an integer) and produces a string where the text is decrypted as follows:

1. Convert the string to a list of integers using ord.
2. Filter the list to remove any occurrence of the value 126 (the tilde "~").
3. The integers in the list are rotated -rotation_amount amount.
4. Convert the list of integers back to a string using chr.