fix: Imporved the encoding charset using the Encoding class

[AffanShaikhsurab]

PR Description

I have imporved the encoding where the user can specify the encoding and that same encoding type will be used to encode the data instead of previously default utf-8

I have used just in built Encoding class in the flutter which provide encoiding as follows as mentioned in the encoding.dart class

    // ISO_8859-1:1987.
    "iso_8859-1:1987": latin1,
    "iso-ir-100": latin1,
    "iso_8859-1": latin1,
    "iso-8859-1": latin1,
    "latin1": latin1,
    "l1": latin1,
    "ibm819": latin1,
    "cp819": latin1,
    "csisolatin1": latin1,

    // US-ASCII.
    "iso-ir-6": ascii,
    "ansi_x3.4-1968": ascii,
    "ansi_x3.4-1986": ascii,
    "iso_646.irv:1991": ascii,
    "iso646-us": ascii,
    "us-ascii": ascii,
    "us": ascii,
    "ibm367": ascii,
    "cp367": ascii,
    "csascii": ascii,
    "ascii": ascii, // This is not in the IANA official names.
    // UTF-8.
    "csutf8": utf8,
    "utf-8": utf8,
  };

we can add supoort for other enocding types using the charset encoding . Please let me how on your opinion .

Ps; None of this is made by ai

Related Issues

• Closes Unable to override Content-Type header #630

Checklist

• I have gone through the contributing guide
• I have updated my branch and synced it with project main branch before making this PR
• I am using the latest Flutter stable branch (run flutter upgrade and verify)
• I have run the tests (flutter test) and all tests are passing

Added/updated tests?

We encourage you to add relevant test cases.

• Yes
• No, and this is why: I would like to see the approch and once imporved i will write the testcase

OS on which you have developed and tested the feature?

• Windows
• macOS
• Linux

[AffanShaikhsurab]

soory for previous pr i didnt knew ai was not allowed for now on i wil make sure the code is written by me

[WannaCry016]

@AffanShaikhsurab is it solved?? can u send an ss that it is working.

[AffanShaikhsurab]

yeah it works i will share you the screenshot soon

[ashitaprasad]

encodingName extraction process is not right. Go through the code base to understand how content type is parsed

[WannaCry016]

encodingName extraction process is not right. Go through the code base to understand how content type is parsed

In this issue the content-type override is due to the http lib so it can be controlled ig so another method i found is to use the parent lib dart.io which gives full control I tried it was working the content override problem was solved but for it we have change the codebase as everywhere http client is used. Is there any other way??